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Home My WebLink AboutHIGHLAND MEADOWS GENERAL AND REPORTS PART 1 LEGAL.pdfHIGHLAND MEADOI.NS Units Filing /12 Filing /12 FiJ.ing /lt Lots I Lot 32 Lots I Tract (Tracts - 31 Duplex = (resubdivided) Tvo Duplexes - 42 Duple; = A Apar tments (Streamside) = B&C-openspace) 62 4 84 150 300 , 75 South Frontage Road Vail" Colorado 81657 970-479-213V479-2139 FAX970-479-2452 Department of Community Development september 25, 1995 Mr. Ross Boyle 221.I Yermont Court vai1, CO 81557 RE: Discussion of issue related to the possible annexation of the Hiqhland. Meadows neighborhood Dear Ross: This leEter is intended Lo respond to your recenL inguiry to Pam Brandmeyer regarding the possible annexation of the Highland Meadows neighborhood, or a portion Ehereof, into the Town of vail's Municipal boundary. In consideration of a proposed annexati-on requesE, the vail Town Council would evaluate a very deEailed analysis of the fiscal, social and political implications of the proposal before taking action. My responce to your inquiry will noL be extremeLy comprehensive, but is intended to highlight some of the pros and cons associated with the idea. The regulat.ions governing annexaLions are found in the Colorado Revised Statutes. This documenL identifies the minimum conEiguous area requirements, notificaticn and hearing process, and other applicable information regulating annexations in colorado. I have included a copy of the applicable section for your review. Shorlly after annexation of a particular area into the To''^tn, the Vail Town Council is required Eo impose zcning on the subject area. A detailed analysis of each jurisdiction's zoning limitations, especially density and maximum floor area allowances, should be conducEed in order to adequately assess the pros and cons of a possible annexation. A majoriLy of the subdivisions in your area, including vail Village west Filings 1- and 2, Matterhorn Village, Vail Intermountain, Vail Ridqe, vail Das Schone Filings 1 and 2, vail- Heights and Buffer creet< are predominantly zoned erimary/Secondary (P/S). The P/S zone district al-lows up to two drvelling units on a parcel , with one of Lhe unies being restricted in size to a maximum of 40t of the gross residential floor area (GRFA) allowed on the lot. {jru"to*ruo Mr. Ross Boyle Page 2 The maximum GRFA allowed in the P/s district is 25% of the firsL 15,000 sq.ft. of lot area, 10% of thenext 15,000 sq. ft. and 5t of any lot. area over 30,000 sq. fL.. A 425 sq. ft. credit is than added for each allowab1e dwelling unit on the property. I have checked with Eag1e County and determined that, the existing zoning of the Highland Meadows area is Residential Suburban Medium Density (RSM) . The RSM zone d.ist.rict allows for single family, duplex and multi-family residences at a densiLy not. to exceed one dwelling per each 8,000 sq. ft. of "net developable 1ot areatr. The person I spoke with at the County told me that. virtually all lots in nighland Meadows are of a size that will accommodate a duplex. Ttre maximum floor area allowance in Ehe RSM zone district is 30t of the net developable 1ot area. Other issues you will need to consider are summarized as foLlows: Votincr Riqhts - Obviously, the ability to participate in local elections would be an advantage that. would come with being located within Ehe Town of Vail municipal boundarj-es. Services - Property owners within the Town of vail receive a level of serwice considerably higher t.han those located outside of the Town boundary. Police Protectioq - If annexed into the Town, the Highland Meadows area would receive more frequent routine patrols than it currently does. Increased paErols are more effective in detserring crime and may also hawe Lhe psychological effect of 'rfeeling" safer in ones community. Additionally, if annexed into the Town, property owners in Highland Meadows would have greater control over the guality of Lheir police proEecEion (calling the Chief or Mayor directly with suggestions or complaints, etc. ) . Fire ProtecLion Although the vail Fire Department will currenLly respond to emergency situations in the Highland Meadows area, the cost of the response, figured a! an hourly rate, is billed Eo the property owner. Also, in the case of multiple calls occurring at the same time, properties within the Town witl receive priority over property locat,ed outside of the Town boundary. Additionally, I have been told that fire insurance costs may be l.ess for propert.ies located \,tithin the nearest fire protection district boundary. Mr. Ross Boyle Page 3 Freouencv of snow plowinq - During the r/inter months the Towl has a snow plow crew on duby 20 hours a day. I believe thaE it is safe to assume that, if incorporated into the town, the roads in Highland Meadows would receive snow plowing sooner and more frequently than they current,ly do. St.reet cleaninq - The Town provides a total cleaninq of all streets in Town every summer, with additional cleanings provided on an on-going basis, as needed. Road maintenance - The Town's road maintenance program includes the annual maintenance of all roads within the town, including crack and pothole repair, slurry seals as needed, shoulder repair, etc.. Addit.ionally, a weed growth inhibitor is applied to all road rights-of-way each spring. CapiLal improvement,s - Although the Town does have a very aggressive capital improvements program, any new roads added to the system would most likely be placed at, or near, the bottom of the current list of improvements. Desiqn Review Board - For properties vrithin Town, all revisions to the exEerior of a builcling must be rewiewed and approved by the Town of Vail's Design Review Board (DRB) . The DRB may require revisions Eo proposed projects that would not be required in the County, where DRB review is not necessary prior to the issuance of a building permiL. Real Estate Transfer Tax - In 1980 the Town of vail established a fund to acquire and maintain open space wiLhin the Town. Under this program, know as Lhe Real Estate Transfer Tax (RSTT), the Town collecEs 1B of the amount of the sale price of all properLies that are sold. Negotiating who will pay this tax (buyer or seller) and its possible affect on the sale price of the properLy is not a consideration for property owners outside of the Town boundary. Propertv tax assessment - It can be assurned that property taxes are higher for propert.ies within the Town than those outside of the Town boundary. I have spoken Co Steve Thompson, Town of VaiI Finance Director about this issue. Steve informed me that the currenL difference in assessment between the Town and unincorporated Eagle County is 4.59 mi1Is. Therefore, property taxes in the Town are $469.00 bigher for each 100,000 in assessed valuation of the property. Mr. Ross Boyle Paqe 4 Buildincr permit fees - Although the Town of Vail and Eagle County use the same method of assessing buildinq permit fees (based on a schedule of varuation contained in the uniform Building code) the Town modifies the schedule depending on which of four zones a property is located within. A1 though f cannot. provide an exact comparison, I believe that building permit fees, charged for new construction and remodels in the Hiqhland Meadows area, would be anpohere from 20 % to 70t higher within the Town of Vail. The cost of annexation - The costs associated with the initial annexation proposal musE. be carefully considered, including but not,limit,ed to, legal and surveying fees, preparation of det,ailed cost/benefit analysis, etc. . I hope ttre abowe information is of use to you as you consider the pros and cons associat,ed with a possible annexation into the Town of Vail. If any additional information is needed please do not hesitate to contact me at 479-2138. Sincerely,kk Senior Planner cc: Pam Brandmeyer Tgn Moorhead .{ixe Motlica file ?rrr coPY TOIYN OFVAIL 75 South Frontage Road Vail, Colorado 81657 303-479-2 I 38 / 479-2 I 39 FAX 303-479-2452 Deparunent of Community Development August 11,1994 Mr. Richard L. Gustafson P.O. Box 1063 Vail, CO 81658 RE: Highland Meadows Geologic Hazard Reports Dear Dick: Thank you for your recent letter and attached geologic hazard reports lor the Highland Meadows area. As you and I have discussed with the Planning and Environmental Commission (PEG), the geologic hazard reports that you have submitted have not been adopted by the Town Council for inclusion into lhe Master Hazard Plans ot the Town. In order for the Town to formally recognize these geologic hazard reports, it will be necessary for the Town Council to adopt these studies during one of their regularly scheduled evening Town Council meetings. It was not clear in your letter as to whether or not you are proposing that the Town adopt these geologic hazard reports to be included in the lvtaster Hazard Plans for the Town. lf your intention is to request that the Town adopt the plans, then I would like to outline the steps that must be taken in order to provide full public disclosure lor the adoption of these reports: 1. A written request must be made to the Town, specifically requesting that certain geologic hazard reports be adopted and be included in the Master Hazard Plans of the Town of Vail. This request to amend the Town's hazard regulations must include a $200.00 application fee, per Resolution No. 10, Series of 1991 . 2. An up-to-date list of all the property owners within the study area, including their mailing addresses, must be included with the request. 3. The Town Engineer shall review the requested amendment and additionally, the Town shall reserve the option of obtaining the services of an outside consultant to provide professional advice regarding the proposed amendments. Should the Town decide to secure the services ot an outside consultant, then the following section of Resolution No. 10, Series of 1991, shall apply: Resolution No. 10, Series of 1991 (O) "Applications deemed by the Community Development Department to have significant design, land use or other issues which may have a significant impact on the community may require review by consultants other than town staff. Should a determination be made by the town staft that an outside consultant is needed to review any applications set forth in this resolution, the Community Development may hire an outside Mr. Gustafson August 11,1994 Page Two consultant. lf the Community Development does hire an outside consultant, it shall estimate the amount of money necessary to pay him or her and this amount shall be forwarded to the Town by the applicant at the time he files his application with the Community Development Department. Upon completion of the review of the application by the consultant, any of the funds forwarded by the applicant for payment of the consullant which have not been paid to the consultant shall be returned to the applicant. Expenses incurred by the Town in excess of the amount foMarded by the applicant shall be paid to the Town by the applicant within 30 days of notification by the Town. This resolution shall take effect immediately upon its passage." 4. The Town of Vail will then notify all of the property owners within the study area ot the requested amendment to the Town's hazard regulations, and setting forth the public review schedule. A review of an amendment to the Town's hazard regulations involves a public meeling by the Planning and Environmental Commission (PEC), as well as an evening meeting with the Vail Town Council. The role of the PEC is to review the evidence submitted and to make a recommendation to the Town Council. The Town Council review of lhe request would be at a regularly scheduled evening meeling and the adoption would need to occur via resolution. The above is intended to give you a rough idea of the general parameters of the proposed hazard regulations amendment. Depending upon the implications of the amendment, it may be necessary to have several public worksessions with the PEC as well as with the Town Council. lf you should have any further questions or comments, please feel free to call me or Tom Moorhead, Town Attorney' at 479-2138 and 479-21 06 respectively. Sincerely, U* h,<z- Mike Mollica Acting Director of Community Development xc: Bob McLaurin Town Council Tom Moorhead Russ Forrest t Fl!-E copy MEMORANDUM Tom Moorhead and Mike Mollica Kristan Pritz July 21 1994 Geologic Hazards Investigation and Subdivision Evaluation for Highland Park Subdivision, Highland Meadows Subdivision, and Vail Village West, Filings 1 and 2. TO: FROM: DATE: SUBJECT: Attached to the memo are the sections of the Hazard Regulations which relate to Dick Gustafson's request to add the above studies to the Town of Vail Master Hazard Plans. Section 18.69.030, 18.69.031, and 18.69.032 all relate to the adoption of hazard plans for the Town of Vail. My opinion is that in order to adopt this plan, the following steps should be taken: 1. All property owners within the study area are given public notice of the possibility of adopting this study and its implications on development in the study area. This meeting should be held at an evening Town Council meeting or regularly scheduled Planning and Environmental Commission (PEC) meeting. 2. The Town Engineer reviews the study and perhaps a second outside opinion is obtained from a consultant to make sure we agree with the study. 3. Assuming the Town Council wishes to adopt the plan, the plan would be scheduled for review and adoption by the PEC at a regularly scheduled meeting. 4. The Town Council would adopt the plan at an evening meeting by resolution. Depending on the implications of the plan on various properties, it may be necessary to have several worksessions with the public. lf you have any other questions, give me a ring. --ffi o t:{r/romtorwnlY - rfNl11JL1Lryteeq From the desk of. . .Tom Moorhead r { /1// ,(""* P*t /,t, re /ilru,* RICHARD L. GUSTAFSON i;,_::;.:":^"o a1*a 13o3t 4?a-927C June 20, 1994 Honorable Peggy Osterfoss, Mayor Town of Vail Vail, Colorado 81657 Certified mail, return receipt requested Dear Peggy: During several discussions with staff members of the Planning Department and testimony which I gave at the Design Review hearings regarding my concems about proposed construction in the Sierra Trail and Alpine Drive area of Highland Meadows, I have referred to a specific Geologic Hazard Report about that area. This is the same report which the Town of Vail used in previous meetings with the Eagle County as far back as 1986. I have been informed by staff that such a study does not exist in the Town files and therefore can not be considered in any discussions about the hazard concerns in the area. Since the study is not available to the members of the Planning Commission, or to the Town Council, they should be provided a copy of the report before any construction is approved in that area. The report makes very specific recommendations regarding site-specific hazard studies, curbing and drainage recommendations, and sloping and retaining of areas adjacent the roads to prevent serious movement of unstable soils. lt also raises serious questions about the advisability of any further construction in the area. Please see that a copy of the report is distributed to all members of the Planning Commission and the Town Council before any further considerations or approvals are granted for any construction in this area of West Vail. It may even be appropriate for the Town of Vail to consider buying some of these questionable lots with funds from the Real Estate Transfer Tax fund to prevent future unnecessary liability to the Town and the taxpayers of Vail. rely 7 tlt Richard L. Gustafson RECENED FEB 2? IW EAGLE CCUNTY 75 roulh trontege road Yrll. colorudo 81657 (303) 476-7000 ofllce of town altomey February 77, 1987 Eagle County Board of Commiss P. 0. 8ox 850 Eagl e, Col orado 81631 RE: October 16, 1986 l4cGrath Gentl emen: i oners Memo Regarding Highland Meadows The Vail Town Council has asked me to respond to the memorandum dated 0ctober 16, 1986 prepared by J. Nicholas McGrath relating to the Highland Meadows subdivis'ion. The memorandum js misleading and inaccurate. Some of the obv'ious misstatements are as follows: 1. The memorandum states that from conversations with Susan Vaughn geologic drainage and stab'i lity concerns exclude the Tract A area of Highland Meadows Filjng No. 1. 0n the contrary, one of the buildings located on that area, the c'l ubhouse for the Streamsjde Condominjums, had extens'ive soiI instabil ity problems during constructjon. 2. Mr. McGrath states that not all the numbered lots actually have problems. In reality, the studies indjcate that alI the lots have at I east some minor problems. 3. Mr. McGrath states that the Town of Vail subseguent to annexation of the subdivision issued a single family bujlding permit on Lot 3, and four duplex permits on Lots 8, 9, 18 and 25. In fact. the Town has issued no permits for single family buildings and has not jssued four duplex permits on Lots 8, 9. 18 and 25. In instances where the Town has jssued building permits, it has required site specific geologic investigations and appropriate mitigation measures based on the 'investigations. Moreover, contrary to Mr. McGrath's statement that the Eagle Cbunty Board of Commissioners February t7, L987 Page 2 County of Eagle has issued no building permits, jt js our understand'i ng that the County has issued building permits in areas with identified soil instability. 4. The memorandum states that Lots 26 through 42 were approved by the Town of Vajl as a special development distnict to be called Highland Park, but that neither the developer nor Vajl recorded the plat until recently. 0nce again, the memorandum misstates the facts. The plat for any units built on Lots 26 through 42 were filed prjor to the issuance of the certifjcate of occupancy. If in fact McGrath's memorandum is correct and Lots l through 42 of Highland Meadows Filjng No. 1 contained plat restrjctions preventing the issuance of permits until the subdivisjon improvements agreements were complied wjth, why were those restrictjons removed by Eag'l e County before the property was annexed by Vail and why weren't the restrictions djsclosed by the Planning staff of the County to the Town pri or to annexati on. The Town of Vajl disagrees with the tentative conclusions reached by i McGrath and, of course, disagrees that "Vail's authority and approvals far outweigh and supersede Eagle County's actions." The appropriate time, both legally and practically, to have addressed the soil 'instability problems was during the subdivision process and prior to the sale of the lots by the developer to members of the public. Although the Town of Vail is willing to work with the County to address any problems that exist in the Highland Meadows Filjng No. l area in a cooperative manner, the Town has no intention of annexing that area until such time the County agrees to participate in such sol utions. Very truly yours, &^"- fl hZ,> Lawrence A. Eskwith Town Attorney LAE/bsc I.IEMORANDUIT To: Board of County Cmissioners EROH: Beth A. t{hittier, Eagle Courtty Attorney DATE: April 3, 1985 RE: Highland Meadows Attached are copies of the geologic hazard reports :':egarding Highland Meadows which the Town of Vail referred to during the joint Tohtn and County meeting held March 18, 1986- BAw/af cc: Susan Vaughn, Planning Director Doug Pilcher, Public Works Director ,V&.-1 fl,( 4# hu,^ter'dr "fuk ia^ ^ r* ' '/'; d 4 C,laycomb Eng i '/ r.t.Lage plaza cl.enwood Spri 30 90; neer i ng r sui re 207 n9s, Colorado g1601 GEOLOGIC HAZARDS SUBDI VIS ION ;IIGHLAND PARK Augus:16, L9B2 Attn: Mr Elmer Claycomb Rr.r: INVES TI GATI ON EVALUATION SUBDIVIS ION HIGHLAND I,IEADOWS & v;i ;";?;;^H",#!';,'H?ii$i.:' l*:FILINGS 1 & 2 WES? VAIL, COLORADO Dear Mr. Claycomb: ,i:::!ii:!i:: :::=::ff,ji:,ff":]:i :f a_ceo,osic Haza-s ri:.ehtand Meadows ana ili.shia;; ;;;::.i:':1.5". Hiehtand park,/arr. virlase wesr Fili;;;-i";";=;:"i; ;:li";"ii; j;rlijo". respectf ulIy submi tted, Li]ICOLN-DeVoRE TESTING LAB., INc. 1 .."-:. l.r,i lfuzn ',."!Lm,/n'-h *".jo3 .lo. 4.1 708_GS _ -.-. ,_._,_ - 'r:inO JUnC:i Jn ,'J - :r - u_! eni.rood spr i ngs 1^ Cr'-r,r-cc -trrt I n,ar, - )t ot^Co :ac.'.t ). . ,'/r..r.t.' -A TABLE OF EONTENTS !95I". of ?ransmirral IUPJU of contents r.a 01 e of Figures INTRODUCTTON GEOLOGIC SETTING r:eorock ^ i,Iinturn Formation Surficial Deposi ts __ Debris Slide Glacial- Moraine Terrace D epos i. ts rar .F.dlt Deposi ts Co]_l uvi um a l:lg:l iu" ;.;i""f:"*ash Depos i rs Solifluction Recent AlI uvi um Recent S l urnps .-;EOLOGIC HAZARDS r,rope Stabilit.(z :"::u.face Drainage Soiis Ilazards Oebr i s F lows Seisnic tisk t =r?::.t.t "- l:: i"3t DES rcN.q rroNs iazard;"-;: tiazar,J;;;^-: ,.14 za r d Area 4S ;ldza!. d Aro_e A/-:laz;rd ar--- ^;iazarc.? -qi=" jc i:zarC ar-.e ? ::aZJf C A rar ?^J6 :ta:ard ,irA-r 1/\ ,iisT.ABLE TILL SLOPES ttl?i"Ir t"i,r rvA.LUA.rroN .it:ical .qreas .{ I TI GA Tr OTJ Page I 4 5 t 7 1 8 o 10 IN IJ. T2 IJ 13 1.J.O 'l ', 20 2T 2I 22 4Z 22 ZJ 23 a, .+ 1A zo )', )o 11 37 j I I I Figure 1 Figure 2 Figure 3 .trigure 4 Figures 5 Figures 5 TABLE OP FIGURES - site Location Diagram - Geoiogic Map - ceologic Hazards Map - Subsurface Drainags Map A&B_orillinglogs A e B - Soil Sumnary Sheets (in pocket) (in pocket) (in poqk.i; I a I a t i Il'TRODUC?ION ;;:r.j"tisation and "":" rorrowins pres west Firings .ws' Hi-ohland Mead vision anarysi""nt" results of a the inves,rn",rt .n6 2' in ,oest 'ot" Filing No' '' ot otnnland Park' seorosic hazard on was to ia"ntrJ- t^ti .t"t""to.,;-:.lJ;t"J::"t" ;;iT ;:4: ;:'' ; ::"1;':i::' and P"en'|ial those areas whic tions on the ",tn" nuotogic settl"" tnt existing :econnendations ,h Possess subsurf ieisions' uno 'tnn' to identify ,,i rhin rhi" ..o".t.'. mi:isate iden,;,":';j-;:,t"" t ..t;:' '::":"' al so i nc.L udeci roS gdthered f,- rnformation incluc irre sia" aunr. 1) reuiew of n"xr '' ed in this report . j""'; ;:j:: :j,::.';",""',"ff ;";; "* "j' :: ;::j iire e:<cavation ng of the si te geolosy'""r"r:at:;J'ogic reconnais- ci high ar.titudof six explorato""t"nt and geologic hazards' 4) anaiysis. r,r",l aerial onoton'.ir"':""t"i"t;'r":l interpretation cie period of "."uto napping for tr,i" "t"aJ'r"^:':totttation and .;j;:' .:"J:'.,:' ;;. t*li':: ;:1;:" c'nduc'|ed rr'n ., '.i """" "". ,J;,:: ,:..:j:;j ';:T: :i'.": "" ;:;"1;: l,' ::i;,e::onpanvins rhe sketch ff "#Il:?:',ins maps' j !::.';;-;:;::: ;; ;;ff;":j",I,,:.?^D^oue Bi retto. ,,'nn'uno Meado!,s ' "ii;t*j*$i;ii:iff s::rij';"F:ii$;,; :c(?;.r Vai i, \ s soc i . J" J :. ;il;r; ; f i " iJiJi,. ii i";,f: :, i, i lj";;: 1u",, on, ,1,',,=:" -l:p"iiiilnril'r.',.j:ffn:.-"g1rQn""i::e vair ;t",.,:::,,:i';ff.jl#:i;11:.53,',n1.i3:j"i"":;,-:;;j:"i";"",=W: ?.r:: "".-irt s1,+ ;iif'.'1.. - :4€;)' ;ip" oLr r.r.>or 1-, and, Geologicai ' ' , - t ltnn *". J b{ro.j: r.'ision, n,j "Xiljigation, vail . .- r....,i - r-, ^^.rr.-,.. _ - --..' tvv LD€D & Associaces, ';i'.;";";;;nI-?r 1j shrand Mei :., .r:-.:,ic:i -<,." i".:::j::::";,;.:eadows, r!7 26777, by chari.s r : - ,.,;;,;n;; ,i^i:;;iiii'J',,'7)r)i6. uutt villaee ,./es r, : : :::.: obser"^"::::.9-crycu'6"1"u_r.rants oF r.n*^-; ;, 1 t;;i;:.jl $ :5"5';iii"::-'-;;;::':;.ccmPaction ': :':, :,.r prsp,a:l;::^;;: f;;; ;:';ii*iiL :'l"tli;i,i:;', .-'=,, ll.:;ii:;;i::irii':::::;:ji".. "r"'in"".1, ;;':i vai,, .. - ' j ,]i::ti; ^::fi|;and Meadows bv crr, rhompson rnc. , : - ., ";;ishla",i',::::.': So sropu , : t:, i;;.,' i,)r;lli:;; ;;ii: 6:i5::"!i'i,"o."r;nnis .,'' i.;i:"5";::i:ii;*, ll::o:.;3n,f lgu i.s.emen ts, Lors ' j-r.,, iared;'i);;;:1r.rt1s I . .: ::,: Soits r.,l--1:1:: Jtr.n *upil rerrv Klug and :.I :.--:_' Soils 1,..,u-' -1 "' twr En maD) . - '--:t q'ru . ., ::.;^,;;i ie';'i.ijijj,ii;,ff:*::o.,parxine Lor and r - : a9 No. L, sv ri"""i" jJ"rlo.uSt_ 24, .vair viirage . . ...l.isiirrr-i^- vgv\JrE t'estrng Lab., rnr= !.!c ._..- -,:-,i,r i,les r. n.:ti"g iiolu".J r r_ ,n,.,.'''-;;:n,,ive pian) ro"n "i"""rluo:^ !u componenr of tl::::,a1"^,, vct\!, source, Arthur 1.rt::,...tr.::li'ardFoundationInVesh].iri|i'.. ;l:;:;::,'.,,'.j :j::: Fii;;;"J"i ";";;';;ii::',,1",'"'iillil",ill;;;;;j;',,::.:.,f r"." r""";.;;. ,1,"' rhonas E' sunmerr€ ; :r.-",1' j, \!rriern".n viirl;.-';;#:.:,:i9 slope srabitiLy f;;:: , ';,llTl,": t,., i)i);;. "uooivision, riri"g-j rv i-' t'.'l l ) ;. c: ,,, ; "-: ": = , . v,,/ 2 4 / 7 4 . --"' r'rrrn$ Z b! {t,;:'-t_.', .,. i."-, r;lg1;leers. r-'rn " ,:. .r':, =-..:. {o. - z,-l,ii)ts.''' regarding Matterhorn ; ' . :.'.:s:i gation. r.^F r 1 ur;19 Ldb. , rnc. ,,,.il,rilii,',::!'ii',i:::llt: :";iili,f',',nn "o 2,,,;.'i,?ix";:":i;;;::,:lili'ilil:ii?rt,jirins vo 2, ''.',',1;1;l: i";J,;i:j;$;:ix::i',illii;n'iio'i, u"', dr;; ::;i:;{, .;:";:;i.i::::,, i: ?.Fii::i;i,:ti:iiif:: i;;: :'i:iil "" l:l-r;-'i'Ji"^li;;.,''lJi;,'."Jii5J ii;);;' ;i=;, :; r;jf i,;j::i:i:ii;:: !i;;tio;;:.;, a";;;;t.:i il' i,",, r:ttiti'i,';,i$ffi #i::;ii':*i:iif il', -?- 2S) Soi. l rnc 2 7 )," li.:;;e-:, :"; i ii";,i";;,;;jj :,, - uO...,':,,':T$i{#iitf i";:ir::";i;L}*iT=Tt*ltif :' ;;, ;:$i#$:,,"ii'*f".i.#*d:$ir:;:' rnc resa:ri rs ; ;$'4i$i#'"m:l-t"', W'ffi ;i , r) "rl;t*!. 'Jr;:""ffJ'^"::^i;;igl: i;::, T:i)iT:"., Hishr and 3 4, .":i ;5::. i:i'l;;::!tii,t:tli,,:;;; !)rg.,:!Lws sub<ji vi si on i s ) .. : ;.T' ;i T ::^ {:;;ii n3,''i T; =:;;: i:i,';;;: : . \lili}8 .,., ea dcws ',,, ;ii ###,, iii"rdi :;,;;T ;, :',, "l:c* i "T ^.Tff 'i:: " " " ; *r'..,l.+ffitli5dffi;,'_T ."-' "" r,, . i t5i".tffii" i{3ll:i jiifr i :ff t;ti;t. ::'ri ; ;: ;n, jJu.ro, nn j 2 .'*ii*',*:i,ffifi*;11il: ;,, :r:;::' and l.Iest vail the Highland Park' Highland Meadows l'iling l_ and 2 Subdivisions are locared on the soLrth side of core Creek in i,lest Vail, Colorado (see Figure L).The iopography on the three sites is rrariabre, with sl0pes and 'to'o.lr:hpic features being r_he resuLt of the va:ious geologic lorocesse's in rhe region. rn aighland Meadows Filing No. 2 and scutherly portion of Vaii Village l{esL, Filing l, the topography is dominated by moderaLe to steeply sIo-oing northfacing slopes,aith local shallower portions. fn the west part, a smatl area of nighland I!eadows, Firing 2 conta'ns gently to moderately sroping ground' This gentiy to moderately sicping ground continues into cne iIi'lhrand i''teadows area, where a portion of the eastern part conLains simirar gentle topography. To the south and h/est,righiand Meadows and Highland park contain moderaEe to steeply ';J'oping ground wj. th a rnain cirainage,ray which biseccs the si te..\long the northern porLion cf itighiand Meadows FiIrng No. l and 2, along wi th porri,:ns of vail ViIlage hrest f ilings I and 2, is 'ery steeply sl0ping ground descending to the area of Gore creek i.-ri r ts tr i bu tar i es . s!e!_eqrr_sese are dcrninated by mocierate to .;ci-'rCherl-v :Dar t, and generaily arc easter. y portlons. vail vij.Lage .v{est Iilings steeply slc.oing ground in gently sloping ground in Land2 |.l^^ the north the site consists Throughout the been ccvered by which wiIl form Bedrock underlying oi: ihe t.li.nturn formation of pennsylvanian Age..li.,cri:-v of this ar,:a, the i,tinturn pormati.on ira;:jr! icia1 jeposits, rvhich ar? the geologic units l I I the majoritr olhe materiaf types an.a "o be encounrered during construction. The l6q61ion of the various geol0gic units are shown on the Geologic Map (in pocket). Eedroc k ---- Mi nt urn Formation (nrn,y., As previously urentioned, the Minturn !'ormation is covered by surflciar deposits throughout the entire site. Five outcrops of bedrock were found during this investiga_tion' one outcrop was observed in the back portion of Tract c of iiighland Meadows. another below the existlng cul_de_sac of Verrnonc Road in the Highland park,/strearnside area. Rocks exposed here consisted primarily of interbedded sandstonesr pebbly sandstones and s6ngl6merates. The rocks dip at 16 to 20 dec nor rheas r, whi. ch i s consi stent ,", .n .n" ;;;;t.:"". tr;":;:" tt" 'rrea' ?he other three outcrops were found in the rowest parts of che site easterly of streamside and consisted of moderately frac_:ured and jointed sandstone and pebbly sandstone. ALI strikes rere northeast with northwest dips ranging from 25 to 60 deqrees.rhe'se steeper dips are generalry consistent with regional dips of cedrock across the Gore Creek Val1ey. Dips are steeper with the predoninant dip towards the northwest. ?r.eo faults which offset :ne Minturn Forrnation (but are conceared by surficiar deposi ts)lave been mapped as underlying the site. The change in attitude cf the rocks is thus probably due to faulting arthough they may ,;:::."" iarse blocks or displaced bedrock .eithin rhe debris rn the ri t -, ,Qion, rhe i{inturn conglonerates, imes tones. shales) are l irnes tones ar e The northerly facing slopes on the sites and northerly dipping bedrock form a dip sl0pe condition rvhich is ccnsidered to be unfavorable for stability. Although the true dips of bedrock are, in sone cases, steeper than the siopes on-si te' the apparent <iip (that cornponent of <iip rneasured 1:erpenci j.cular to t.he slope) are in sone cases shailower. The <iepth to bedrock will vary con_siderabiey over the site, depending on thickness of surficial :ieposi':s' Becirock rvil1 possibly be encountered at the toes of scne slopes i:r the 1o."rer reaches of the properiies or possicly in tie':p '=;4srrations, ar.:hough !hroughout the majority of the site -fr-'a' bedrock will probabJ-y be deeper than 20 feer and possicry :s deep as r00 teer' No betrrock was encountered i.n any of the t:';t nof es drilled in conjunct-i'on wi th this investigation ai though test no-r-es by oihers r3por tedJ.y encountered bedrock at a ieprh of 70 feet on !.ct 22t Vaii Viltage i.fest, Filing 1,. at depths ringing from 6 :o 51 feet in the HigirranrJ Meadows subdivision; and ::.: Cepth of 5 feet in the valley botton which divides :liqhlanci park and Iiighland i,,teaio,n/s. Forinat i on consi. s i I ts tones and The cl_ as ti c un i 9ener a1l_ y brown lighL gray. sts of interbedded sandstones, shales, rdith some interbedded 1 ts (sands tones, siltstonesr dDd co reddish in co1or, lrhile the : rrF ^i -'r!.r! ! ^t- rdi .JeDCS: :S I)':Lr i:r q I i,'ln tr')dc I .tvurr./ . An ancient Cebris slide is the sur_ ircial deposit vrhich underlies the majority of Highrand Meaiows !'i1i.c No. 2, the southerly portion of Hi.ghland Meadoers Firing No. l, and the southerly portion of Vail village West Filings No. 1 and 2' This debris siide extends a few thousand feet upsrope !o :ne southeast. C. S. Robinson (in a Ietter to Mr. David El:ror e -, I z;,i 1. City Corporatr.on, dated March 11, 1975) describes !-he r)iocess oi failures in the area. when the bedrock sropes were ::l'::er cr-rt fy "... strean erosion as a result of the mer:ing of the '1-':ciers, the bedrock slopes failed and formed r,andslides. These ':lcce fairures did not happen all at one time nor at one prace. ;lre cli.f f would fail by the undercutting of a sandstone red_oe by I sirean. fn su:sequent years the shale slope above the sand_ '; :rr': Lvoulc cecome saturated and fair forming a mudflow out -tr:.ss rr3 orevious landslide- The erosion of the toe of a -'rnisi i.ce woutd reactivate part of an oLd landslide. These slopes il'/e :ail-ed iocally nany tirnes as Gore creek has continued to r:oCe its channel. The resutt is a deposit that ranges in irickness over the bedrock of a few feet to more than 100 feet rno 'rir icn consi.sts of brocks and boulders oi the more resistant r:d:.)cl< uri ts in a siI'-y, sandy and Iocally clayey matrix. Slope 'rllrre is conti:ruing in parts of the area, and wiII continue '::tiess sceci.ai- ef f orts are made to stabilize the area.,, Materials cf the debris slide depo_ : !-' r :.: ::<?r>sed in nunercus cuts in the roaci system. For the i r-- r-'"'- pclril :he ie.trr -.; si i,le ccnsi.;is of sil_tv and sand.,, clavs I '1 E t i rJ -7- ili ji i I I l,l!ll rl I I a -a I i o o ccntai.ning smalr to rarge amounts of angular gravel- and rock to :oulder si,ze, and consists rnainly of materials develcped from the )linturn Formation, The ,.jebris slide deposi ts contain scattered rhin to thick zones of materiars which classify as clayey, silty, :irc gra're11y sands. These deposits can be descriced as an uncon- sorirjated heterogeneous mixture of soil and rock, with no strati- fication or structure. Scattered slip plains are probably pre- :ent withi.n these deposits. Portions of the debr is slirie :r:criai have been reactivated in the recent past. Reactivation .::.; :opa:ently been causeo both by natural Eactors and by the r;crks of nan. This is evidenced by the verl, recent slumps in r:n'.' :oaicuts; the landslide which occurred in !tarch of this year rir \./ai i vilJ_age west, Filing l, Lot 22i other possible slumps or si-iies which have been mapged on the site; and by nspring tine :cirps" p;esent in and to the east oi Highland Meadows. It is prooaSle that the debris slide is not active "in mass", but that :ouLd not be determined under the scope of this investigation. Giacial i,loraine (Qm) : Morai ne deposi r,s of glacial and/or glaciofLuvial ori,;in are inferred to underlie the westerly part of aighland Meadows, Filing 2 and a signi.ficent area of Highland ll:aoo'.rs, !'iIin_o I anci iIighland Park. These .ieposits are Ehe base )r'r/nich the terrace-J.ike topography, previously rnapped by other :ui::rrs, 5as ceen f ormeci. The morai;re deposits consisl- of an u;iccnsciidated mixture oi clay, siLt, sand anci gravei- (to boulder -3- l i I I I I l I i I t, I d -9- size). Most of o rh e gravels and cobbles are brounded to rounded cut are mixed with some subangular fragments in the fine grained natrix' rnspections of ^.e road cuts and exposures arong with bne data gathered in the t?st hores indicates that nost of the upper surface of the moraine has been modif ieci and covered by georogically more recent surficiai deposi ts incruding randslides, colluvium, sropervash, organic crays, and possible sorifruction deposits- scattered remnants of moraine are probably present on other portions of the site as evidenced by 10ca1 steps and brnches- The moraine rests on a bedrock surface above the pr e- sent elevation of Gore creek as indicated in two expcsures. rn iie exposure on Lot 1 of Highland lteadows, Fi1 i,ng 2, the bedrcck.,/ 'oraine contact is separated by disptaced bedrock fragnents of debris slide or colluviun. T.-r: ace Depos i ts (e t ) : Two different levels of river ierrace deposi ts are present in Ehe site area. The mos: recent terrace is the sands, gravels and cobbles, whicn a:e presentry be!ng depcsiied and eroded in the flood pl-ain cf Gore creek. T5e second levei is terrace deposi bs rocated above the physio- graphic froodprain, adjacent to the Gore creek drainage. These jeloslts can be found in tire streamside subiivision and in por- ir ons oi vai'1 village ivest, ?iring l.ro. z. These terr3ces were ieDcs;. ied by Gore Creek at !ines r!uring F-he geologic past, the lji.ihest.errace ceing the oldest. TypicaJ.ry, these deposits con- sist of unconsol-icated, erudellz strati,lied inixtures of clay, o JLI 4d i 'l ': i t i: I - q>rrd >^,.1 i ql-i ^a: l v rrr,--1.. - rock tyPes, and cf roundness, gravel (tc boulCer size). The), are character- r:ei.:' io pocrLy soried, contain highly va::3bLe al inost aII the gravel particles show some degree Ailuv!ai Fan Deposj.ts (eaf ): Alluvial fan deposits can be founci e:("encing from the nouths of the larger drainageways on the sub- ;ect si:es. The largest of these deposits are located in tire streamside subdivision and the northerl-y portion of vail viirage :fest I and 2. These deposits.resulted frcm depcsiticn at the rcuths of the larger drainageways, anci characteristically consist cf non to crudely stratified mixtures of clay, silt, sand and gravei. Since they are the deposits whi.ch tormed from the i:eining oi the basi:rs in the area, these deposits consist of a nlxture of virtually aII the other rock and soil units expcsed wi:hin their drainage basin. Typically these deposits are uncon- scl i d: ted, 1:corly sor ted, and contai n gr avel to boulder sized .oar "-ici-es wiih varying degrees of rounCness. Colluvi'rm and Slope Wash Deposits (Qc-Qsw) : DeposiEs of colluvium and slopewash cc\rer the najcrily of ilighland Meadows and Highland Park, and :.-'l-:t',',ie\'y r--hi n d:_:csi:s oi siopew3sh cc;er ti:e terrace level i.a ti-re t/aiL Viilage i.lest, fiiing 2 area. ColLuvium anC slopervash n3:-sriaIs are Ceposlted by the actions of sheetwash, graviiy, - l_0- .:! shallow slumpin o 9a nd landsllding as the result of erosion and mass wastinq of the steeper slopes to lhe south of the site. F,or the most part, these materials appear to be derlved from weathering of tbe Minturn Forrnatlon, h,ith some materiars con_ sisting of both Minturn derived nateriars and arr.uviun or moraine. These deposits are sinilar in character to the debrls sii'de deposits, and consist of an unconsoridated nixture of soir_ and rock' rn the areas dominated by poor subsurface drainage conditions, these soils are wet to saturated. rncruded with the slopewash deposits are layers of organic clay (encountered in Test Holes No. I and 2) apparently deposited in pre_existing Cepressions and/or spring areas. The older deposits such as moraine are covered with these layered roixtures of the naterials. rn iTrost cases' the coarser sl0pewash deposits and colruviun cannot ce distinguished from debris slide naterials. Landslide Deposits (e1s): A few lanCsli.de oeposits have been rnapped on tbe site. The larger of these deposits exists in the norLheast portion of the llighland Meadows on the steep s10pe which descends to the Streamside Subdivision. The other rnost significant randslide exists in the area of the cur-de-sac for vernont court in Highiand park. The presence of the randsride fr-'atures indicates that sone readjustinent of surficial depo.sits ('' addition to the debris slide) is arso currentry taking prace, or has taken place in the recent geol0gic past. very recenr - r1- movement i." ",ria.,!d by rhe retarively ,r""n?urps ar of the slide above Streamside. The northerly tinits of verxnont court landslide courd not be deternined at this to road and building construction. Several other smaller landslides and possible slides have also been napped. .fhe najority of lhese features appear to exist on moderate to very steep sropes, and appear to have resurted from a ccmbination of undercutting or o'ersteepening of the sl0pe by Gore creek and/or by saturation of the slope by springs and seepage. In the area of the slide at Termont court in ttighland Park, it appears that this feature is a ::su1 t cf saturation of naterials on noderate to gentre slopes. rn addition Eo these randslide areas mapped, the presence of smeLr scarps in other areas of the subdivisions (see Georogic Ita.o) indicates that other areas of possible srnarl sruaps and sli- ces exist. The many guestioned features are a resurt of the fact that placement of utrrities and construction of road and fllls tave obriterated or disturbed pre-existing natural features and vege tat i on Sci.if iuction (esoL): A few possible sol iftuction sones r:ve been napped on-site. These occur in the extrene westerl!, portion of Highland i,Ieadowsr Filing No. 2, in Highland Meadows; :nd lIighranc park. sorifruction is a form of soil creep and can -1e described as the process of slow f l-owage f rorn higher tc rower ground of masses of soit saturated.rrith ieater. possicle the head the tine due - LZ- I mapoed on-site. - rl- o the o solifluction has occurred as the result of saturation of colluvial and slopewash materials (and possibly noraine) by springs' As has been indicated in alr previous investigations, :lurnerous springs I seeps and rret areas are f ound on si te. Areas previously nappe'c by Robinson and Thompson as tongue_shaped robes in an active groundwater zone are 10r were) possible solifluction areas' chen (in 1972) napped an area in the region of Lot g of iighland Meadows, Filing No. 2, as being characterlzed by ,active spring sappingn. This area could also be rnapped as .posslbre solifluction- the lrcs.sibre solifruction zone which extends down frcm Meadowbrook Drive degenerates into a landslide at the break in slope above Strearnside. The possible solifluction area extending from ltighland Meadovrsr Filing No. 2, LoE g, is charac_terized by a distinct head scarp, active spring, a distinctive bulge in the slope as shown by a togrcgraphic map and a conspi_ cuous grove of aspen in the down slope area. Recent Alluviurn (eal ): . Recent alluvium can be major drainageway which bisects Highland Meadows. consist of a mixture of sand, si1t, clay and gravel ceing deposited and eroded in the strearn channel. Recent SIumps (ess): found in the These deposits currently Several recent slurnps have been For the most part, these slumps occur in the road -1, - 14- o crrts of Highland Meadows, Filing No. 2- It appears for the p3rt that these slunps have resulted fron the saturation (by surrace seepage ) of the materials exposed in the road cur-s ldebris slide materials). only the larger or nore significant slumps in the Highrand Meadows, pllrng 2 area have been rnapped. It shouid be noted that most of the road cuts within the Hrghland Meadows, Filing No- 2 subdivision are characterized by rirl erq- sion, sheet erosion, small slumps, and/or thin oskin_type, fairures, and were either too snall or too 'umerous to map. The snall slump mapped in Lot I of liighland Meadows, Filing No. 2 at Gore creek consists of both s::vere gurr-y erosion and smarr.slunping as the resurt, of erosion ani saturation of srope nateriars frorn the surface drainage. Two ot5er recent slu-'nps were tnapped in a northeasterry portion of ;lighland Meadows, Filing No. l, in the landslide deposit which is locaied northerly of vermont Road above the streanside subdivision. The northerly of these two srumps has occurred uphilr from a gaSion wa1l constructed as part of the devel0pment of streanside. It appears that this slump occurred prior to construction of the warl but nay have occurred when the cut for the walr was nade. The other slump is located near the head scarp of the landslide, there muo has slumped and flowed down srope. with the exception of ,"n': 'ossible area easterly of Tract B, no recogni zable recent srumps were noted within the nighland Meadows or ilighland park road cuts- rt should be noted, however, rhat most oE the cuts. 'rrthin nighland Meadows are lower and/or laid back at a shailcwer angJ-: than those in Highland lrleadows, Fii-ing 2. The cuts asso- ciaied wirh the realignment of roads in tiighland park had not moat sub- o Seen coropleted at-the tine of could not be observed. thi,; investlgatlon, and therefore, Observations of the cut slopea along -\lpine Drive and Sierra Trail ln Vail Village West, Fiting l, indicates that most of these sropeE ara very Steep but nort arc not as deep (higrr) as the ones ln Elghland Ueadowa, flltng l. The cuts are eharacterized by rocar srnalr slurnping and erosion which has resulted in t.he undercutting of the vegetation rnat which cap the cuts. seepage ln the area of the cuts rdas noted to be minor at the tine of slope inspection (g_3_g2); but condltions in the spring of the year may differ. r - 15- .c J. - 15- ' lEOLQcrC HAZARD ,r! The nost significant geologic razards which affect the site are (l) the presence of unstabile -nd potentiarry unstable sl0pes (incruding mapped randslices), :21 the presence of areas characterized by poor subsurface drain- age and (3) areas of possible present or past solifluction. other :iazarJs which affect the slte incrude variabte soil conditions iiircruding expansive soils and soils prone to settrenent or con_ eclidation), the potential for debris fIows, and eartbguake ira zards. Siope Siability: Three najor factors result in the presence of unstable sl0pes and potentially unstable slopes in !he subdivision areas. These are (1) topographic setting, (Z) g=ologic setting, qnd (3) surface and groundvrater conditions. topographically, the subdivisions are dominated by moderate to steep to 10ca11y very steep sropes rvhich are a part of dominantly northwest facing sropes of a rarge lldge' Areas of more gentle topography can be found in the iortheast pcrtion of the site area (in vail vilrage west, FiJ_ings I end 2),' along Gore creek at various points; and in the area of !ilghi,and i,teadows and Highland park. Geologlcally, virtually the whol.e :ite is underlain by rerativery thick unconsolidated surficial deposits of various types. ;{ost of these deposits contain a substantiar amount of clay and sirt size part.icres l.ri.thir !hern. oo 510pe stability ls thus controlled by the strength of tbese materials (along with noisture, slope, etc.) rather than by the strength of bedrock. rE should be noted that bedrock ln the site area is also ln a dip srope condltlon and tbus oriented unfavor_ ably. the site is located on a northerly facing slope- North facing slopes accumurate very rarge snow packs' evaporation is less than on southfacing slopes and thus nore accumulated moisture is retai.ned in the subsurface. poor subsurface drainage conditions resurt, for tbe nost part, in (and f ;om) numerous springs and seeps on the site. These springs and seeps, along with water which percorates down through the soil as a resurE of precipitation and snowrnelt, decrease the slope stabi_ l-ity by saturating the subsurface soils. ?he presence of E.he possible sorifluction zones indicate that even the gentler slopes can becone unstable if saturated. Our lnterpretation of t.he geologlc hazarcis present on-site can be found on the Geologic Eazards Map (i;r pocket). This map is based on a review of previous studies on the sites, and our additionar field investigation and mapping. iazard designations as shown on the Georogic Hazards Map are Ciscussed in a later section of this report. Subsurface Drainage: Subsurface drainage conditions cn the site can be divided into two broad categories. The first is surface and subsurface flow associated wi!:r Gore creek and its ( -rr- .A tributarir"' O" second 's surf ace un,, S"u.f ace fl0ws asso_ciated with springs and seeps. subsurface sr High groundrdater tables and areas of lepage can be anticipated as the result of tbe water table assoeiated with core creek' and with possible percbed water tabres and subsurface seepage associated ,{ith the two main tribu_taries which enter the sites. In th.e case of Gore Creek, high groundwater conditions can be anticipated in those areas underlain by the rower revels of the terrace deposits arong Gore creek' rn addition, those areas of alluvial fan deposits adja_cent to Gore creek can also be expected to have high groundwater tables as the result of the.same condition. Those areas mapped as alluvial fan deposits (Qafl 6in1rt also be expected to contain l0cal or seaso_na1 sha110w groundwater tabres and l0car areas of subsurface seepage fron surface and subsurface f10w froru the najor tribu_taries and upslope springs. By far the most critlcaL conditlon in terms of s.ubsurface seepage on the srte rs the poor subsurface drainage conditions which exist as the result of the nunerous springs and seeps' Throughout the hillside area of the sub-divisions, nunerous seeps, springs and wet areas were noted during this investigation and have been the subject of much discussion in previous reports, letters and field reporEs. ?he seeps and springs in the arga are erratic' This is the result of the wide range in character_istics of the soil materials and their permeabilities. Seepage follows t:e "path of ieast resistance" which in these types of de.oosi ts is not o usu ally predictable because their non- sr*ratified nature. The amount of and rocation of seepage at a particular time of year or during a year rs also controlred by many variable factors which vary fron year to yea; and season to season. rn the exrrerne westerly poErlon of fJ .l ihe nighland Meadows, Filing No. 2, and the easte: l)"-!y :n part of ,i$ilighland Meadows, Filing No. I area, it appears that the najorlty of the seeps and springs originate near the topographic break on Natlonar !'orest proper.ty and in the southern and eastern part of this area (as recognized in previous investigations). Another area of rather intense past and present spring activity is lccated northerly of vernont Road in the regions of Lots No. 2r, 22 and 23 (Hiehland Meadows) at the 1andslide scarp and bench. Areas characterized by poor subsur_ face drainage conditions, wet areas and seeps and springs are shown on the Subsurface Drainage Map. This is a conpilation of data and spring rocations based on our investigation and previous reports and data available to us. fn actualiiy, the entire site area can be characteri zed as possessing poor subsurface drainage ccnditions' rt appears that sone of the areas presentry exhi- biting seeps and weE conditions were either not recognized in -orevious irvestigations or were not present. As deveropnent of ttre siies has proceeded, more and more seeps, springs, and wet areas rrave been encountered, or uncovered. rt is rikely that.as nore rjevelopment occurs, adciitional areas of seeps, springs and rvet areas will be found. An interesting note fcr the ar3a e:rconpassing r{ighi-and pa:k is that ihi.s particur_ar:ar: or !he o of -t9- iidge is characterized by an wise doninated by evergreens, moi sture condi tion here. Summary Sheets !- or 5A and B and 6A and o " islar,d" of aspen in an area other- indicating a probable higher SoiIs H a zards: Fron a soils englneering standpoint, the site soils possess variable engineering propertles. Although nost soils probably possess bearing capacities high enough to support light1y loaded structures, moderate to higb loads rnay result in some settlenent or consolidation of the soils. Areas cf rather low density high moisture content soils were found in the test borings (particurarly Test Borings No. 2, 4, and 5). uncier these conditions, even lightry loaded structures may require special foundation considerations. Since tbe najority of the surficial deposits contain at.least some elay in significant, guantities, expansion of the clay soils could also be considered as a poten- tiar hazard in the subdivision area. Expansion pressures on the order of 900 psf were measured for both soil types encountered in the tesi borings. The basic soil conditions for individual sites should be taken into account during the individual investigatlon for the structures for each lot. The logs oi Test itoles and Soil the soils encountered are provided as Figures B. -1 -20- Debris ptows: O Review of the Geologic-Rapicl irlass I{asting process Map (a conponent os- the cornprehensiee pr.an, ?own of r73i1) indicatas .!-hat the two tri)utaries cf Gore creek ehice cross through the si'!es haTe been mappe.i (b'Arthur r. uears) as possessing a moderate debris flow hazard. This map described these hazards as'areas included within this category can experience property darnage, including f100ding, erosion, inun-dation by mudr dnd impact by small boulders. ft is unlikely Lhat life will be endangered in Level l areas excep., at the very erratic and infreguent intervals of unpredictably rarge rockfari and debris avalanche events., The debris flow bazard areas as indicate<i on this map are shown on Ehe Georogic Hazards Map accompanying this report. Seismic Risk: The subject subdivisions are located approxinately. six miles southwesterly of the Gore FauIt. This lault is considered to be potentially active (R. M. Kirkharo and ;tJ-' p' Rogers, 1gg1), and consist.s oE a complex f aurt zone about 70 kilometers iong and up Eo about 4. g kiloineters wide. Because of the proximity of this potentially active fault in addition to the potential earthguake hazard in this region of Co1orado, the srte is consi,lered to be in Seisnic Risk Zone 2. This should be rsken into account during foundation and stability anarysis for ccnstruction in the sub<iivisions. -2I- The geologic hazardS p!€sc)..1 : :.r_s:. te have been categorized based on geologiq unitT topographic seEcirg,and surface and subsurface drainage conditions. ?he hazarjs designations are shoefn on the Geol0gic Hazards Map (i:r -30c<e:).The following discussion wiIl serve to descrlbe these cLassifica_tions. For the nost part, these designatlons correspond :o those mapped by previous investlgations; however, they bave been nod:_fied based on the additional geologic mapping and analysis con_ducted as part of this investigation. ft should be noted that the hazard areas and s10pe stability characteristics are cas:d on theoretical analysis. site specific studles ruay concJ.ude ihat hazards are either less or 'greater depending on site s-oecif 'c geoiogy, slope, noisture conditions, etc. I{azard Area 7 _ physiographic Floodplain: These areas lie within the physiographic fl00dplain of the core creek crainage and its tributaries. rt should be noted that along Gore .lreek eonsiderable construction has occurred, and man_nade features have obliterated the pre-existing physiographic frood-plain which probably existeo_ in this area. ft is our understand_ing that !,ederal fnsurance Adnrini rhe !.roodprain rimi." ;;;r;rnrstrarion uaps exist which show Creek. The floodplain lirnits on Ehese naps should be checked in order to verlfy that buildings and lots are located outside the floodplain. Hazard Area 6 _ Eazard _A,rea 6 generally consists of GEoLCGTc Hazls ossicNarroNs: "::::l:.l::u_^".""rabre slopes in acrive sroundwarer areas. rhi.s des i' gnation generalry characteri zes ara'a ^. --^ .. -"=! ar ecis ' Tnl Srooes - 5,rr- j .,^ ^ -"qrqvLBrrzes areas of very steep to steep ;,';;;; ;:; oo si-umps t and,/or past novement. This clesignation is mainly Iirnited ;o napped landsl_ide deposits. fnvestigation of these areas for ccns:ruction is likely to be guite expensive anci mitigation 1:.keiy to be quite extensiye. Depeniiig on speciiic cons:ructi.on a;rd condi tions, deve j.o.omen: rDai/ not be eccnonicai. On otller por_tlons of the property bordering these areas, investigations for construction shour-d anaryze the effect of construction to these s10pes' Adeguate setbacks from these areas should be rnaintained. irvestigations for stabirity will probabty involve off-site ana_iysis. Hazard Area 5 _ This area designation consists for the rost parr- cf metastable sLopes. This area Cesignation is gener_ aii1" characterized by steep to very steep slopes and accelerate,c .r3ep. Loca-l_ seeps are also present within these areas. Con_ s--ruction in areas designated as Hazard Area 5 wilr reguire a very detailed and probably expensive geotechnical investigation, anc probably very extensive rnitigation. Depending on specific construction and conditions, devel0pnent nay not be economical .construction pranned adjacent to the Area 5 designaiion (both near the tops and toes of sropes) shoulc evaruate the effect construction will have on designation 5 area, and effect these siopes will have on construction. fnvestigations for stability ^'ril" .:robably involve off-site analysis. Hazard Area 4s - rhis area designation cons'sts of those :i.-.as ::lapped as .oossi cIe active so1 if i,.rction zones. These arbas r:'r :itarac;erized by probable high grcundrrats_er, ani possicle slop l:.:c:si'.-.r:ieci creep in the form of soLifl_r-rction. Siopes in these ll :as i:neraliy range 5rom gentle !o ncder l:3. In :;lese er ?as, o detailed geotechnical investigations will be necessary in order to analyze groundwater and srope stability considerations arong with foundation reco:nmencations. rn some cases, mitigation wilr probably be expensive, depending on site location in reLation to other hazarC zones, topographi: se..ting, etc. In extreme cases, development nay not be economical. rnvestigations for stability and groundi{ater conditions wilJ. probably lnvolve off-site analv- -: ^-l>. Irazard Area 4G - This area designation consists gener- a1ly of potentially unstable slopes in active groundwater areas. This area designation is characterized by moderate to steep siopes, 1oca1 seeps and springs, recent but snalr slumping, and/or moderale creep- rn these areas, detaired geotechnical investiga- tions will be necessary in order to anaryze groundwater con- diiions and slope stability considerations along with foundation reconmendations. rn sone cases, mltigacion rvi11 be expensive because of the height of cuts needed in order to provide access and building areas, steepness of slope, and lateral _pressures due to creep. rnvestigations for stabirity may involve off-site ana- lys i s. Hazard Area 4 - This area designation consists of poten- iial1y unstabre slopes. These areas are generally characterized by moderate slopesr possible creep, but appear to be fairly 'dry' al the present time. rt should be nolec that, although areas within this designaticn aDpear to be characterized by low inoistur-o conditions, excavations fcr access or founcations may encounter subsurf ace seepage, I t is, l-_irereiore, very important ihal inciivi,Jual site cectechnicar investigati.cns be perfcrmed -2 4- o pr ior to dr a i nage construction, anC that slope stabiiity and subsurface condi tions be emphasi zed in t,hese invest.igations. Hazard Area 3G - This area designation consists nainly of moderate to gentre sJ.opes in active groundwater areas. These areas are characierized by active seeps and springs or possibre shallor', groundwater tables , and/or possible past so1 ifluction. Detailed geotechnicar investigations are reconnended in order to assess past or potential sollfr-uction, subsurface drainage con_ Citions, foundation conditions and slope stability. lrazard Area 3 - This area designation consists generalr_y cf gentJ-e slopes characterized by apparent low moisture condirions. T'hese areas rnay be subject to, locar or seasonal groundwater seep- p3ge. rndividual subsurface soirs investigations with ernphasls cn subsurface drainage, slope stabirity and foundation conditions are reconunended in these areas. where the designation 3 area abuts against higher hazard areas, the effect of construction on srope stability should be analyzed. Hazard area 3A - These areas consist generally of moderate to gentl-e slopes, generaily above the permanent ground- waier labre of Gore creek. These areas nay be subjeci to rocal or seasonal groundwaLer tables and possible fiooding or debris flows. For the most part, these consist of the alluvial fans in the streamside area and the northeasterly portion of vair vlrlage, Filings 1 and 2. subsurface soirs investigations a!e recommended for these areas with an emphasis on foundation con- ditions and subsurface drainage consicierations. rf deep cuts are Planned in these area6, they shourd be specificarly anaryzed for siabiLity or retained. I - z>- -26- .:: o t, BaaaiC Area 2G - ?his area Cesignat,ion consistE cf, Elac Eo gentle siopes in active groundwater areas. These a:eas are characteri zed by variable solls conditlons, and by a high per_ .iilanent water table. Enphasis in these areas should be dlrecied ioltards subsu:f'ace drainage conditions and foundation conC:tions. ft should be noted that the haz:ri oounoaries, as delineated i:r this report (and others;, are gener_ aily drawn at approxinate breaks in slope and bhat setbacks for the buildings fronr hazard zones shourd be based on the proposed construction and indiyidual geotechnical. analysis, not "bLanket" setback distances. t I I *rto"* "rrrf"o"rr, Another hazard whlch affects the site is thar of porenrlallv un'rabre fill stopes. -{:e- t13t lsll_ll_ _"r9!_.: _:!p*.:1j9_!g tocar ed, ror tbe most part., in Figbland Meadowr =--:--::=l'-'1 rocated, fr s, Filing No. 2, and tn vall H*5:F:-'g:rand2 ;,::ff",..Inspection of the roadways und n"u in which longituciinaL cracking (cracklng parallel t ,vas observp.t ,rL- - -'-"-"r vqr c"Lrel to tbe roadrvay)was observed' rhe nosr obvrous area in which .". ;;;;;;""r"'observed is in the hairpin loop of Alpine Drlve ln Hightand ilX Meadows, Flling No. Z. In this area, lt appears that the road fill is either settling and/or moving down the hillside. Another area of significant crackini is l0cated on the northerry slde of Lhe roadway near the cul_de_sac of Seguoia Drive. Nurnerous other areas of l0ngitudinal cracking were arso noted al.ong the roadway of Highland lteadoersr Filing ge. 2, and in Vail village west,Filings I. rhis longiEudinal cracking rvould indicate either (l)that soil rnateriars in utility trenches are possibly settring, or (2) fill sropes created as a part of road construction are either settling or creeping downsrope' unless the firls were properry placed (with proper stri.pping, keying, benehing and compaction),:he fill sl0pes shourd be considered as potentially unstable, rt is possible that these fills were not .oroperly compacted and/or iie on an unscarified surface of old topsoir and eegetatj.oo, and thus the fill wedges are prone to cre€pr srumping and settlement.Build up of subsurface drainage behind the firrs ,.-"."r ;r"=".presure) or saturation of the filts by seepage wourd also reduce tlre stability of Ehese fill rvedges. Even if the fills were keyed, -27- I I benched, ana lrpacteO, ii placed within o the creep natural soils on the slopes, vernont Road (Eighland Tf not properly placed potentlally unstable. zoi:e oi rnovenent could occur. In the area of the cul_cie-sac :or eark) a fill of substantial heighr .xis.s.and conpacted, this flll nighr also ce tuuotutrtoo, "O,uogro* At the time of the writing of this report' nost cri ticar references were availabre for our review.Review of the subdivislonrs layouts in regards to prevl0usry mapped geologic hazards r,ras acconpltshed. Based on our review cf the avairable references, arong with our field reconnaissance an,j ";al. of subdivision layouts, the folrowing discussion is pre- Vail Vi1lage West I .and 2: rn the case of vail village west,!'ir'ings' No' l and 2, it is'our understanding that these suts divisions were platted prior to any reguirenents for geological or soils reports, and therefore, no previous geologlc hazards investigations have been accoruplisbed for these two filings. Highland Meadows, FiIing Ho. l: The exisging subdivision Iayout, 6s it pertains to original georogical studies and previousry napped nazardous areas, appears to have been planned with due regard for site conditions recognized at those stages, at least to the satisfaction of the various consultants and reviewing bodies.uost consultants indicate in retters that at least the prellni-nary plat had taken into consideratlon known conditions. An area encompassing portlons of r.ots I through g, 12, 13, 14, 15, 19 an,l 20 oi Highland Meadows /fo was apparentlFf,ot part of the study u.""ln the C. S. Robinson and Associates' report dated November 2g, Lg77, but was part of the R. W. Thonpson report of July, L973. rnspection of thls l9Z3 study indicates that portions of the building areas for Lots 6, 7 and 8lie within his,High Riskn zone aLihough in a letter to *KBNA dated December 2, 1977, Thompson indicates: rThe Latest map !curnjshed our firrn indicates substantial portions of f,ots 4 through 9r and 19 to 25 are restricted as open space. These restrictions are within areas described as high hazard zones in our original investigation. we believe the open spaee as desig-nated on the plat should be rnaintained and building restricted fron these areas. n Eigh1and Meadows, Filing No. 2t fn Chents 1972 report ior Vail Village west, Filing No, 3 (Figure lB) it shows an area Including portions of Lots 1 through 5 (Eighland Meadowsr Filing No. 2) as "potential sli de Area'- rhis hazard area is arso shor.rn on the sketch plan submittal Map (sheet 4; for Highland Meadows, Filing No' 2; however' the boundary differs sornewhat between the two meps. Chen's June 30, Lglg, report was apparently not accom_panied by a sini166 fiapr and therefore, it is not knordn from what the hazard area on the Sketch plan Subnittal is based. The sketch Pf,an submittal is dated May, 1g7g; cben,s reporr on ilighland Meadows, Filing uo. 2 is dated June 30, 197g. To our kncwledger the prelimi'nary prat does eot delineate this hazard area on it' rn conclusion, it appears that portions of the L thrcugh 5, "Potential sL i,,Je Jn Sunnerlee,s 1974 report for ryatrerhorn village subdivision, riiing uo- 2, 1t shows an :rea including portions of Lots 15, lo, 17, lg, Lgr 2aand 32 as his Area No' 4 (""a very high risk of sl0pe movenent associated with any construction cuts and firls.,) and Area No. 5 (,These areas are presentry very steep and unstable due to active collu_vial movenent or 'creepr.r)- These areas boundary is shown on the sketch plan submittal for Highj.and Meadows, Filing No. 2 as "Eazard Area"' portions of Lhe building enveiopes for Lots 17,r'g and 19 1ie rvithin this rtsazard Area'. This hazard area is not on the preLininary plan for this filing. rn Highland Meadows, Filing uo. 2,the road systen is such that it is feasible thac access could be obtained from either the top or bottom of the lots. fn the case 'vhere high cut slopes exist on the lot, this creates trrctential groblens in that if access is on the downhill (cut) side, con_siderabr'e excavation will be needed in order to access the building area. When accessing a lot from the top portion, it is usually tre practice to construct a building on a cut and fill pad' 8y doing this, firl could possibly be placed cl.se to the ir:.rt slope which forms the downhill boundary of the lot. The surcbarge of fill sl0pes above cuts could have a detrimentar..:ffecr on cur slope stabiliLy. rn Ehe case of,".".n";;;":-".oei?een thro streets, such as between Alpine Drive/Gore Creek Jriye and Vermont Road/Gore Creek Drive, the construction of cut bui tding Hi ghl and Areai. .nv"Qu" for stine of Meadours, Filing p6. 2) these rorloot" Iie ui:hin this - 31- oo siopes ccur-d have a detrimentai- efiect on the uphirr lc.s ano rons;ruction oi fiil 0n Ehe upiriil fots ccur.d have detrirnenla.l eifects on tbe downhill locs. iii.ghLan<i park: fhe itighland park Subdivision is a replat cf iiighland Meadowsr Lots 26 through 42. This area was covered under the Thompson, 1973 and Robinson, l9l7 reports. The Preiiminary plan for Highrand Meadows (including Lots 25 through 42) was apparentry revieweci by both Robinson and Thonpson and by the Colorado Geological Survgy. The generai conclusion in the Jol0radc Geol0gicar surveyrs letter is: "De,/eropnent of the Ires:-upper:neadow is feasible but like all nountain devel0pments vi.L1 need good construction supervision." To our knowledge, neither Thonpson, Rcbinson, nor the .cororado Geologicar survey have reviewed the Ilighrand park subdivision plans. By overlaying the 1g77 Robinson "Engineering Geologic classification Mapr onto bhe Eighrand park Gracirg and Drainage plan (nevised) dated April 27, 1991,. and .ciocting lhe landslide area indicated by Jerry Kiug and Associates in his letters of November 5, r9go, the folrowing conclusions can be Cr awn. 1) pour planned units (which have already been built) iie rvithin Robinson's En,oineering Georogic classif ieation 5.. 2) portions of Ehree planned unies }i-e within a r-and- ;ii:e aree as identified by jerrir Klug and Associaces. -l -JZ- t' Cri tical Areas Tlre l,ltrrrt"lt luat.lun oi critleal problens and potentiar hazardous areas due to constructlon is cornplicated by the fact that the type, size and nature of as yet unbuilt structures is unknown. Tiiere are also difficultles involved in evaluating the effect of present construction because we have no idea who did the subsurface soirs investigations for the individual building sites, what they found, wbat they recom_ mended, and if the devel0per fo110wec the recommendations. Highland Meadows, FiIing No.,!3 tbe first exanple of a ;rctentially hazardous area due to present construction is the area of Lot 2 of Highland Meadows, Filing No. 2. Thi.s lot is in an area of possibre solifluction- The northerly part of this rot is an area of metastable slopes. rn the area of tots 41 and 42 0f the vail Vi11a9e West, Filing wo. 2, construction has created high retaining walls and high steep unretained cuts in this slope. The combination of these factors resurts in a bigher hazard potential for instabilities for constructlon on this lot. Severe gulJ-y erosion was noted to be occurring at two main points. In t.he Lot I area of Highland Meadows, !'iling Ho. 2 and in Lot 5 0f H'ghland Meadows, Filing iqo. 2. rn Lot 1' surface drainage is directed down a metastabre sLope and the saturation of the soir.s has created a gulry and sJ-unping. rn Lot 5, gurly erosion is occurring around the area of a man-hole and seerer trench excavations and sorne rnud is beinq -33- washed Cown cause sloPe couLd occur o the swalrr. ConEinued ercsion of this area could instabitities and/or deposition of the ero<led soils in the house area inmediately below ..he swale. i ,, : '. I t I ! I I I Vail Viilage ifest, filing No. 1: Another critical problen area ls the '-ot 22 of Vail Village !{est, Filin_o }io. }. Tt appears that miti_ gaiion of the landslide which has occurred on this rot wilr be gulta expensive- Depending on how much rooney could be expended ro:aivage a builiable porEion of this lot, the lot may have to oe abandoned for buil<iing purposes for the sake cf stabilizing the slope and road. potentially hazardous areas exist rrithin the unstudied vail village, f.iling wo. I. In tbis sub_ <irv:'sion, entire lots have been napped as being on metastabre slopes- These rots will require very detailed site evaluations prior to construction, mitigation probably being guite expensive. tighlano park: The area around Vermont Court incJ-uding portions of former Lots 27,29r 29,30, 31, 33 and 34 rs encther critical problem area. In this area, Robinson recognized a iancislide. subsequent irvestigations by Jerry K1u.g '::lj -\ssociates derineated a slice area encompassrng portions of iots 23,30,3r, 33 and 34. A reconnaissance of Ehis area curing _ cuf irvesr-igation alcng with the excavations o! Test 3oring No. I d- -34- o indicates this ar'5 tc be a lanisiirie. We w o nrr ! ) C.Jonsider i,he slice mapped by Robinson anc the slide map.oed by Klug as the sarne feature an<i thus combined and expanoei :he Lwo s.i ide ar:as. Tlis sride area is considerec to be in cur irazard zone 5 anc mitiga- tion of this feature would probably have io involve a combined effcri,:f ai1 l_cts invo1veC. I t i s sugges teti .,-ha t. r-he ilighland Park subdivision pran be reviewed by the previ.ous ccnsuitants and th" col.rado Georogical survey for their comments on the proposed development in this area. Eighland Meadows: fn the Streanside area, a1 though not a part of this studies alea, it appears that previous investiga- tions reconmended filrs in the area to buttress the landslide, while present con-struction has undercut the toe in part. rt is not known whether the existing gabion and retaining warrs in these cuts erere designed as buttresses. cutting of this toe (\ri ti"rout retention ) could have negative ef f ects on stabili ty of the Lots in Highland Meadows above t,his area. Il eg ;. cnal- : The most critical area lies in the :oo: :'lDsurf ace drainage conditions which exist on the si!e. 'rhls, nower/er, can.orobably ce nir--igaLed or sucstanEiarly reduced by an : x': ens i ze subdrain system. d- -35- .l tighland Headows,E tt oo , Siiing !{o. 2 s r/ail ?illage Wes.., i.iliig Nc. i: o The stabiltry of cut slopes in tlighland Meadous, Filing No. 2 and vail villag(: -r{€st, Filing No. I is also a criticar area. As previousry drscussed, nany of the eut slopes in fighland ileadows, giiing No. 2 e;:hibit slsnping, seepage and erosion. These cuts dill continue to fail if not stabilized. The prinary rnitigati.on teitrnigue reconnenied for this area is to instarr a subsurface drainage systen in order to intercept the subsurface seepage. rt rs possibre that buttressing or retention of sone of the cut slopes wilr also be regul;ed. -35- ,J MITIGATICN Many different types of uncon- soiidar-ed surf icial deposits under'1 ie the site and varicus problens and combinations of problems affec'. the site. As pre- viousiy discussed, sl'rpe stability on the site appears tc 5e conrrolled by three main factors, Ehe topography, both surface anci subsurface drainage, and the geol.ogic un.its. Due to these inany variable factors, the type of mitigation used on any par- ticular site or problem area will depend on its site specific characteristics. Depending on the type and extent of the hazard, a jcint effort may have to be nade by Ewc or more lot owners in orier to mi'"igate the hazard. and reduce the potential for insta- 5i fi ti es on thei r lois. In the case cf smal1 r,o mediuil sized landslides, nitigation could involve renoval of the slide debris and replacement with compacted fi11, drainage and buttressing of tae landslide, or in the worsc of cases, complete avoidance of the hazard. In the case of possible soliflucti-cn, this can probably be at least slolsed Eo an accePtable level of risk by a system of drains which drain the water fron the deposii. In the case of gully ercsion' sinple installation of drainage siructures wbich are non-erosive would pr event ,lul ly ercs i on. In the case of the slumping observed in the rcad cuts, a .arefully planned and designed subsurface and surface drainage systen would be the first initigation measure Eor these areas. In so'.ne cf !he cuis, stabilization by buttressi:19 -37- or letaining nav amount of mairtenance which and -'i1l and sheet erosi.on, be r:n.; nay be necessary. o also be required. Depending on the can be tolerated due to ski.r faiiures, slough walls or siough catchment o structures J. fn reference to the poss!.ble norrernent of road fi11s, rni tigati.on courd include continuous rnaintenanee of cracking' stabilization by some sort of retaining structure, or in bhe worst case, complete re:noval , stripping, keying, benching, compaction, and drainage. one problem wi.th the so1 ution of con- tinued naintenance.and cracking is that if the filr moves to an extent chat it reaches a water or serrer line, a similar failure could occur as has on the Bi.tetto property. The primary rnitigation technigue which should be investigated, planned and designed for tbe site is a subdivision-wide drainage system. This point cannot be emphasized enough. This drainage systen should be instarled based on a detailed subsurface investigatlon and analysis of the groundwater. conditions on-slte, analysis of the existing utili- ties systerns (some utirities could intercept subsurface seepage an<i i! not designed to do so, could increase the problems), and careful design. C r i ti cal .or oblem ar eas should be investigated in more detair as soon as possibre in orcer that solutions can be found to these problems. We hope this has provided you with the i;fcrmation required. rf you should have any questicns or reguire adoitionar crarification, please feer free ro contact L i ncol n-D evor a . --1 -34- , :\! ! ,. -J- !,\; - -_/.4= l(*,,..^- ,/ r ,t ,z----"..'/ ,r ,i' ,f:=---i_'- ...t, "r1ptY.' :;ffi',' _ ur,,'r|rt* . -' ,'--:"") i \ , j-- ' rvu<;1.,,,,..r2ft{::i .. ^\ ,, ,,i,,,'..)f-, - t-'-' t;,,', iJ ','-l J- . +"iffi,i' ' -="'/ ","'.,,'F i iv -j' / d N "L i" €Rat stre LocATtoN DtAGRAl/t tAND MADobts I |lf HOLE No' i ELEVATION I Cz ) 62a /, wtu Saern 6?elrE!t, PEz'84,v. ) *2o lt7t F/3/?,, /r,rED. o€'rsr7y, EXPt/,/AtrE, Sat E Ut. S.atDtTaru F,et6*tEY75 8.,OCt CZnl ScFa EE'oP6er//c c/e/, t4'rD/) 5/L7 lr ri,lrt 5a17n 6'?4t/EL F/3,?, ) */at'/ 7o vrET 5e'/tdE ' TYePDER DFtctZO 7-21.z. AF|EP D ree- pf ls D 6l , Czt 2/, ,ft7/l JCa7r. RATELJ, PEO-aP.{., SartSe.!D/) Fra6:t1A/r5 aztcr 6ce/, a16e/16, 5/t7t'altorr , Y.,?t r'f EXPA^/'/ t/€, TF!frle, EouLa€R DZ|LL€O 7-L. AF7€2 I 5 Ne rEA *r/'. alr az21 au, 6r//tr.to/, ?Eo-82^r. FrCrA, /Yrotta txPtlrtv€ 6ate, 'to2E 5e/tD 't't"E, lratl Ot vt/// !12 ro t5 t622 t4'/. 2512 /8.4 5a,|tg 20 ttDe24t OEI&€D 1'7-8 4p7fr. c s Na u47EA ,€/!6t08-€ .54 RILLING LOGS t-t,'rlCOt-N I ccuon.loo, cc'-caA00 sFRl'rjs i o.vOar ! ausauo I iL11)Y.9o?.:iil5:';li-6itig'Ei.s' | 'oa.r*c 'it''ficrlci[ ' T oNrRosE '-aioLoctsrs I r'rourxo: ncgx !!!.'1-1139 HOLE NO. ELEVATION 61,6lty, tv/nv .5co7n 63er€L5- , U*roltl !Ju of.ttrTl, ExPlut/vE 5e.rr€ F/2/t 42 5.4*rE 5e*rE O2|LLED ?-Z -82. g ttoo 4o bt4rel 6Z, cz.l y) tltUf tcarr. 6,earEa') !r'tr-\*.\t4,1) F/2i1.Aaltl jx.ry.ytlla YEptl 5ar4l latf aEJf sllrl 5a,ee .StloYtgntE cl , 6/.e\ E.rr, tar7. 6PatEz', 8',!\*,oel, I nartl axnlttv, 5e/rr! vtzl ,r/FF, /t6*t ota/t 7/ t e /7'. Ao.t2DER DEILT.EO AF7Za I No d.rez tr/z .fiv. 7,,i'z /r/E ta'l Oro t//2 /"1i*,/:t r ', B-e 'Z l/r? rr. t -/. @ r5 tNaTa? v€2/ tosT) ,v6r zt/,'41Di!,vt/fY y;.;t .&r.rz a '7--e AF7E2.8 tlAraz $ra'. F/4u4; -<8 ILLlNG LOGS LINCOLN I ooloaaoo' cJLoRAoc spRrNos, DeVORE l p'JEBLo,6LEHwooo spRrdGs, EllGiHES;1S' I CRANO JUNCTiON , )a0fliAOSE I 6:()L3915r5 |,lyot l,ic: pocr( sptifle s DR o i.l: iuro i S1.:cc if ic 5U^n/vuRY SHE!T I I I t I . :r i.'.r _.flE"tr1-€l,Ot reojyrL{{a2lfl_ iq No. rr-,t DePth ''rretaat ple f'.lo ,-,..,,;, f-id.tl f e5i Dy P.1. , /,)tl ' ILO.O 8q.5 ' 9A2 ' .4, I j ao,/Y) 64.1 \ 54.7 ,DROMETER ANALYSIS: 'cin size (mm) :ih,':.-:s'.oce -i n:ii F ic ".' lndex S'r:-inlcge iiciio 'v r I '.i re rii .: ii:rnge o/o L: rreo i 5hlinkoae o/o t,!Ci-<rliii, : DF' 15i]Y:,{STM i\4ETHOD Opiin"','.:r Llisture Contenf - wo q4 o'to A4c:<imun iW Der:siiy -rd-pcf Cci!ior;:: Secring Rciio (ovl--96 Srreil' /- fr ays A-21 o/o Swe | | cgcinst-864-psf Wo goin 0.6 6EARING: '1/E ANALYS IS: 'lve lrb .7" Pcssing In P lcice K (ot 5u i lcie: \y'y'o:er Ccrr ren ': &) /4,? '1," rf rcvir) (Gs)tb",r ocf Plc:;i: l-lnii ?.'.-- /6.2 o/o Lic,;id Lirnit L. L- zz4 o/o Fl,rsri':i} lr.-iex P.l._ lt.? o/o i'lot':e i lre r.-. iro rnere. (cv! ps l-.lncrnf i i'ei /jompression (qu) _-ps Plote Beriing: i.rches Sett iernr:ni C:nso tidctic n r tr,vt :F.51 l.l | : : %Psr -/o Vo 'Qagg__qe€___z_s_.L 43,O f f Ps ') nr-t r- ': Roric PPM. F/€uze 64 Ll NCOLi.j-De vCil t TESTI NG I-A3CRATORY COLORADC SPRINGS. CCLORADO SOIL ANAI'iSIS ,t' SUMMARY SHEET il Somclj C/. 6znt/- a26.4/c /824€t() ,niicn ;.'64.Z4 O ,rEcDOW' tu'gO/f. |ing Nc 7,tr-2 Cepth ra' irole Nc . ? Nolu,-ol Woter Ccntent (w\ z3.z o/" Specific Grovity (Gs) IEVE ANALYS 15: leve No .7o Possing | /2tl Te*i oy- 4.4. ln Ploce Density (r") pcf Plostic Limit P.L- Zo.??/" Tesi Nc. D,-i'e 44708-GS 7-30-82 t4: 2tl Liquid Limit L. Plosticity lndex L- 33.f o/o P .1. /2.? o/o under Psf Shrinkoge Limit Flovr lndex-?/o Shrinkcoe Roiio ?/" Voiumetric Chonge-7o Lineol Shrinkoge Vo MOISTURE DENSITY: ASTM METHOD Optimum lrloisture Content - v1o /4.7 o/o lvloximum Dry Densiiy -zr4--gcf Colifornio Eeoring Rctio (ovl------96 Swelf ' / nov< o.22 o/o Swell ogoinst-@4-psf Wo goin o/o BEARING: Housel Penetrometer (ov)----,csf Unccnfined Compression (qu)-psf Ploie Seciing:-psf lnches Setrlement roo.o ) g?.7 ) q6.7 8/"q 70.8 ./DROMETER ANAL'/S15: ioin s ize (mm)7o B?oo 42.5 'po5 ?E I Consoiidofion a/o P ER IIEAB I LITY: t,/€L,,z€ /-6 SOIL ANALYSIS ?noa\ Rotio Sulfotes PPM. LI NCC L,\l-De .iCR : TESTI NG LAEORATOP.Y CC LCP.,ADO SP.C ! NGS . COLORADO K (ot Void FOX & ASSOCTATES OF COLORADO, tNC. CONSULTING ENGINEERS AND GEOLOGISTS DENVER OFFICE 4765 INDEPENOENCE STREET WHEAT RIOGE. COLORAOO 80033 (3O3) 424-s578 Town of Vail 75 South Frontage Road Vai1, Colroado 81657 March 15, 1984 Job No. 1-1101-6244 Attention: Mr. Stanford K. Berryman, Director Department of Public Works/Transportation Subject: Proposed Scope of Services and Estimated Budget Costs for a Geotechnical !!udy for Highland Meadows, Vail Village t.Jest Matterhorn Village Subdivisions in Vail, Colorado FOX & ASSOCIATES OF COLORADO I NC.Revi Regi onal and Dear Mr. Berryman: At your request we have fonnulated a scope of services to study the geotech-nical conditions for the subject subdivisions. This scope of lervicis is pre-liminary in nature and is intended to aid the Town of vail in coordinating a regional geotechnical study. Should the project become viable, we would 5e pleased to provide a more specific proposal based on the final determination of the reg'ion to be studied and the needs of the Town. Additionally' we have provided budget costs for najor tasks in the study which g19,uasg! in part on our.experience in Highland Meadows Filing l and Highland Park._ These are provided for plarining purposes and can be reiined when the actual scope of services is better defined. t'le hope the attached scope of services and cost estimates are useful to you in planning for this project. If we can be of further assistance, please cil 1. Donald R. Pri nci pal I aik,- P. E. Geotechnical Engineer P"r"tl?/lM Rona'ld Project RFH/d1h F. Holcombe, Geotechni cal P. E. Engi neer A FOX COMPANY INTRODUCTION The Town of Vail has recognized the need to ensure that mountainside properties are developed in such a manner.that they are safe with respect to geoiogic haz-ards. It has also been recognized that these potential haiards ar6 not-govern-ed by property lines and, therefore, they are most effectively studied oi a regional basis. The purpose of this proposal is to present a-philosophy for pursui,ng such a study, together with a scope of services that would cbmirrise it and the estimated costs to complete it. The project area consists of the following subdivisions: Highland Meadows, Filing t Highland Meadows, Filing 2 Vail Village West, Filing 1 Vail Village West, Filing 2 Matterhorn Village Our previous work'in tiighland Meadows Filing l concluded that the most import-ant factor affecting development is regional slope stability, or the potential for a major landslide._ Our knowledge of the above project iiea suggelts that regional stability will be the'important factor in ttrii project area as well. It is our opinion that a geotechnical study of a single lot, or a series of such studies, could not adequately address regional slope stability. There-fore, we have formulated a scope of services that will address the regional factors. ^This study could then be supplemented as necessary by site ipec.ific studies of each lot. This approach minimizes the cost to eich-property owner,prov'ides a means for protecting property owners from adverse efiecls d-ue to adjacent construction, and provides the Town of vail with a basis for evalu-ating building permit applications. SCOPE OF SERVICES lrle propose a scope of services that will include four d'istinct tasks as follows: Task I_ - Regional Ana'lys'is, Remaining Lots, Highland Meadows Filing 1 Task II - Regional_Analysis, Highland Meadows Filing 2, Vail Village iusf I I I -lfik filirgs 11 and 2 * and Matter:horn Vil lase Task IV - Probabilistic Analysis Each of these tasks could be performed independantly with the exception of Task III. The street evaluation will require test hole ind laboratory iata that will be generated in Task II. Alternatively, 'if Task III 'is to be doire independant'ly,a scaled down drilling and testing program could be incorporated into Tisk III.-- The purpose and work vle propose shou'ld comprise each of the tasks are discussed in the following paragraphs. The budget cost estimates are presented in the section ESTII'IATED C0STS. -1- The purpose of this task is to eva'luate the reg'ional geotechnical condit'ions for lots in Highland Meadows Filing l that havi not been studied to date. Each lot wi'll be delineated to show recommended buildable and/or non-buildable areas and preliminary recommendations will be provided on an individual lot basis for other soil related items such as'landscaping, subsurface drainage,construction methods, retaining wall considerations and earthwork. The recom- mendations will be developed to maximize the utility of each lot while mini-mizing the potential negative impacts on adjacent property. To accompli.sh this.task, we propose to use existing test hole and laboratory test data developed during our previously completed study for other lots in Highland.Meadows Fjl!ng !. The data will be analyzed to develop appropriate recorrnendations which will be presented in report form. The report'witt ais- cuss the geotechnical conditions and reconmendations for the entire subdivision and will include individually tai'lored preliminary recommendations for each lot.Finally,.the report will contain recormendations for further study, if warranted to finalize the design criteria to meet Town of Vail requirements and ensure that the proposed structures are properly engineered. The purpose.of.this_task will be identical to Task I. To accomplish this task, however, drilling of test holes, a fie'l d geologic reconnaissance and a labor-atory testing program will be required to provide a basis for the analyses. l,le propose to drill test ho'les to bedrock within the street right-of-ways. The number of test holes will be approximately one third of the number oi lots to be studied. The test holes wi1l be dri'lled at locations and depths suitable for defining the_regional subsurface conditions. A laboratory testing program will be performed on_samples recovered from the test holes to evaluate the physical properties of the overburden materials. The results of the field aird'labora-tory_portions of this task will also form the basis of the analyses proposed for Task III. Task I -ional Analysis, Remaininq Lots. Hiohl Meadows Fi I i The analyses and report format for Task II will be identica'l to that discussed above for Task I. Task III - Streets The purpose of this task is to study the subsurface conditions as they apply to the streets in the study area. Particular emphasis will be given to imUiirtirent slSpe design, drai.nage-conditions, subgrade and pavement comfonents evaluat'ion, maintenance considerations, and recommendations for improvements, if indicated. The field and laboratory data for this task will be developed as part of rask II. 0ther data to be used in this task will include the oiiginal'design data, as-bui'l t data, quality control reports of earthwork and pavement constiuction, Task II - Reqional nnatysis, ttighfand -2- and the perfoymance history of various portions of the streets. The results of this study will be presented in report form containing our evaluation of the road system and recommendations for furture maintenance. A probabilistic analysis is a speciallzed study that attempts to quantify the probability that a particular event will occur. In the case of construction 0n-mountainside property, we know that eventually, on a geologic time scale,failure is a certainty. However, the chance that this titturi will occur during the_useful life of the construction is not known. A factor of safety is generally used as the basis for design of slopes; and, in the case of ma-n- made embankments, we know that a particular factor of safety will provide a reasonable degree of safety. For natural slopes which are constantly sub- iected to_active geo'l ogic processes and where there can be great variability in subsurface conditions, a computed factor of safety may not adequately describe how safe the slope is. This generally causes the engineer to use conservative estimates of the soil strength properties to ensure the design is safe. This often results Jn some areas having a higher than reasonabli degree of safety and a similar'ly higher cost of development. l.le propose to develop a probabilistic model for the study area to provide greaterinsight as to the safety of various areas and provide a basis for determining what areas are suitable for construction. ESTIMATED COSTS l'le have developed estimated costs for the four tasks discussed above. These costs should only be used for budgeting purposes at this time. A study of this nature is very difficult to estimate beforehand. l.Je do believe these costs reasonably reflect the-magnitude of the value of these services based on our previous experience w'ith similar studies. TASK ESTIMATED COST I II - III(A) -rrr (B) IV $ 15.000.00 150 ,000.00 20 ,000 .00 35,000.00 15 ,000 . 00 is based on performing Task II prior to IIi(B) reflects the cost for performing The estimated cost for Task III(A)or concurrently with Task II. Task this task independantly. -3- i.,1 ,:., o FOX & ASSOCTATEA OF COLOnAD(', lNC. CO'{SUUNN(r ENq|NEENS A'iIO GEOLOGBTA DEI.|VER OFFICE 4735 NDEPENOEI{CE STREET WHEAT FIOGE. @LORADO 8@3I' (3@) 424-5574 GEOTECHNICAL STUDY FOR HIGHLAND I{IEADO}IS FILING NO. I, AND HIGHLAND PARK VAIL, COLORADO Prepared For Highland Meadows Lot OYrners Job Nunber: 1-1101-5916 l{overter 4, 1983 A FOX @MPANY FOX & ASSOCTATES OF COLORAOO, tNC. CONSULTING ENGINEERA AN9 GEOLOGISTS DENVEFI OFFICE 4765 INOEPENDENCE STREET WHEAT RIOGE, COLORAOO AOO33 (3O3) 424-5578 Highland Meadows Lot 0wners c/o Michae'l Lauterbach P.0. Box 3451 Vai1, Colorado 81658 References: 1) Fox & Associates of and Letter Contract 2, 1983 November 4, 1983 Job No. 1-1101-5916 Colorado, Inc. Work 0rder Confirmation for Geotechnical Services dated June Subject: Geotechn'i cal Study for Highl and Meadows Subdivis ion, Fi1in9 No 1, and Highl and Park Subdivisjon, Vai'l , Colorado 2) Executed Acceptance Form of Reference No. 1 by Michael Lauterbach, President, Highland Meadows Trust dated July l5' 1983 Dear Mr. Lauterbach: Presented herewjth is our report of the geotechnical study for Highland Meadows Subdivision, Fil ing No. ' 1, and Highl and Park Subdivision, Vai1, Colorado. This study was performed in accordance with the scope of services outlined in Reference No. 1. This study was initiated at your request in response to Town of Vail Ordinance No. 29, requiring detailed geotechnical and slope stability analyses of lots in the referenced subdjvisions. I'le appreciate the opportunity of being of service to you in this phase of this project and look forward to assisting you on subsequent phases. Fox & ASSoCIATES 0F C0L0RAD0, INC.Reviewed by: Q,^uZ?,Ah/' Rona'l d F. Holconbe, P.E. Project Geotechnical Eng ineer RFH/cp Copies: 25 Donald R. C1ark, P.E. Principal Geotechnical Engineer (.-j A FOX COMPANY TABLE OF CONTENTS I NTRODUCT I ON SUMMARY GEOLOGY Introduct ion Site Conditions Geologic Setting Bedrock Geology Surf icial Deposits and Geomorphology Hydrology Geologic Summary Geologic Hazards DATA ACqUISTToN Field Investigation Laboratory Testing Slope Incl inometers GEOTECHNICAL CONSI DERAT IONS General Literature Review Method of Analysis ENGINEERING ANALYSIS Gener a l Regional Slope Stabil ity Hazard Area Classif ications Surface Water and Ground Water Earthwork Foundat ions Detai led Recommendat ions PLAN REVIEll AND CONSTRUCTI0N INSPECTI0N RISK General Factor of Safety Probability of Failure Intensity of Study Cost-effectiveness of Solutions GENERAL RECOMI'IENDATIONS Regional Slopes Local S'lopes Page 3 3 4 5 7 8 9 10 L2 20 20 20 20 2L 23 24 24 T2 13 14 l4 15 T7 14 25 26 z6 26 27 28 ?9 29 29 30 TABLE 0F C0NTENTS (Cont.) Drai nage 0verlot Grading Foot i ngs Basements/Foundat ion Wal I s Floor Sl abs LOT-SPECI FIC RECOMMENDATIONS Page 31 33 33 34 34 35 Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. Lot No. LIMITATIONS BIEL IOGRAPHY I, Highland 2, Highland 3, Highland 4, Highland 7, Highland 10, Highl and 11, Highland 12, Highland 16, Highland 18, Highland 19, Highl and 21, Highl and 23, Highland 24, H ighl and 1, Highl and 2, Highland 3, H ighl and 4, H ighl and 5, Highland 6, Highland 7, Highland 8, Highland 9, Highland 10, Highland 11, Highland Meadows Meadows Meadows Meadows Meadows l.,|eadows Meadows Meadows Meadows Meadows Meadows Meadows Meadows Meadows Park Park Park Park Park P ark Park P ark Park Park Park 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 ol I LLUSTRAT IONS Geologic Map - Highland Meadows Depth to Bedrock - Highland Meadows Geologic Map - Highland Park Depth to Bedrock - Highland Park Rotational Slope Failure Progressive Failure Sequence Ideal ized Probabil istic Di stribution Slope Hazard Maps (Highland Meadows) Slope Hazard Map (Highland Park) Details of Drain System Figure 1A 1B 1C 10 2A 2B 3 to 40 to 4N 4A 5A 5E TABLE 0F C0NTENTS (Cont.) Benching Detaii Natural Slopes Regional Underdrains APPENDIX A TEST HOLE AND LABORATORY TEST RESULTS Highland Meadows: Logs of Test Holes Logs of Exploration Holes Sununary of Laboratory Testing Particle Size Analysis Charts Unconf ined Compression Test Results Swel l-Consol idation Tests Slope Inclinometer Fie'ld Data H i gh'l and Park: Logs of Test Holes Logs of Exploration Holes Summary of Laboratory Testing Particle Size Analysis Chart Swel l-Consol idation Tests Figure 6 7 F igure A1-1 A1 to Table A1-10 A1-11 to A1-14 A1-15 A1-16 to Al-19 A1-20 to A1-23 A2-l A2-2 to A2-8 Table A2-9 A2-10 to A2-11 A2-12 to A2-15 APPENDIX B Preliminary Earthwork Specification - Overlot Grading Page B-1 to B-7 { NTRODUCTION This study was initiated by a group of lot owners in the Highland Meadows Filing No. I and Highland Park Subdivisions in Vail, Colorado, to satisfy Town of Vail Ordinance No. 29. A geolog'ical/geotechnical reconnaisance study for the general area prepared for the Town of VaiI by Cl aycomb Engineering Associates, Inc. identified the need for 1ot-specific and regional geotechnical and slope stability analyses to evaluate the potential hazards to developrnent. This report contains the results of those analyses, together wi th eng ineering design and construction recommendations and, where appl icable, identjfication of those specific areas where additional studjes may be required. The project area is located in Section 14, Township 5 South, Range 81 West, of the 6th Principal Meridian. This location js on the south side of Gore Creek Canyon on a general 1y north facing s1ope. The extent of improvements in the two subdjvisions presently consists of paved roadways and underground utilities. In the Highland Park Subdjvision, some structures have been con- structed on Iots not included in this study. |.le understand that the proposed structures for this area wjll be single to four-plex residential buildings of one to three stories in height. Construction of the superstructure is expected to be primarily wood frame. Designs for some of the structures may include basements. At the time of this study, design of the structures had not pro- gressed to the point where proposed grading, retaining wa1 1s, or building footprints were available. The only topographic information available to us was regional topography using ten foot contours for Highland Meadows by KKBNA, and a topographical survey using two foot contour intervals for Highland Park by Johnson, Kunkel and Assocjates, Inc. }lh ile this topographic information is adequate for analysis of regional stability, more detailed as-built topography using a one foot contour interval should be used for final analysis and develop- ment of construction details. _1_ SUMMARY The results of this study ind'icate several significant conclusions. l,le believe that the concerns expressed in the Claycomb Report and Town of Vail Ordjnance No. 29 are very well founded for this and similar subdivisions. The conclusion of this study is that the most critjcal factor affecting development is regiona'l slope stabil ity. A major slope failure cou'l d easily destroy one or more structures as well as pose a threat to human life. Some areas of the site were found to have slope stability conditions which present,.in our opinion, an unacceptably high risk for development (Classification 'D' and 'E'). Therefore, we recommend that no development or construction of any kjnd take place in these areas. Some marginal areas (Classification'C') were jndentified which further study may show they will be reasonably safe for development. Because of the relatively high degree of variabil ity in subsurface conditions encountered, these areas could not be conclusively analyzed on the limited scope of this 'investigation. It is recommended that no development take place in Class 'C' areas unless further study confirms a reasonable degree of safety. The second most important factor effecting development that was identified by the study is local ized slope stabil ity. In our opinion, local stabil ity problems pose a minor threat to structures and human 1ife, and for the most part, can be mitigated. Recommendations were al so developed for foundation design, underdrains, retaining wa1 1s, floor slabs and overlot grading. It cannot be overemphasized that the geologic processes of erosion, weath- ering and landsl iding wil l, in eventual geologic time, remove al I of the overburden from the mountainside. Although it may take many years to complete this process, these factors are active and pose a threat to both existing and proposed structures. As a result, no structure, no matter how welI it is designed, will be absolutely safe and will be subjected to some degree of ri sk. -2- tle as have attempted in this study to quantify the risks and make recommendations to what degree of risk is reasonable and acceptable. GEOLOGY Introduct ion The project site, consisting of Highland Meadows Subdivision, Filing 1, and neighboring Highland Park Subdivision, is located in the western portjon of the Town of Vail, Eagle County, Colorado, more specifically described as portions of the SE 1/4, SE 1/4 Sec. 11, and the NE 1/4, NE 1/4 Sec. 14, Township 5 South, Range 8l West of the 6th Principal Meridian. The Highland Meadow Subdivision is approximately 16 acres subdivided into 25 individual lots; of these 14 lots were included in the investigation. The Highland Park parcel covered in this inves- tigation consists of i1 lots and is situated just southwest of the Highland Meadows parcel. Site access is gained from Interstate 70 at Exit 173 by way of Vermont Road and Meadowbrook Drive. Site Condit ions The site is located on a sloping terrace on the south side of Gore Creek Canyon. The approximate range in elevation is 7900 to 8200 feet above mean sea level. Average s'lope grade on the Highland Park parcel is 28 percent. t.lhile the flatter portion of the Highland Meadows parcel averages only 15 percent grade. The terrace lies at the toe of a moderately steep ridge to the south that rises to more than 11,000 feet elevation. The northwestern border of the site generally parallels Gore Creek, a perennial drainage tributary to the Eagle River, which is approximately 2 miles downstream. A tributary to Gore Creek separates the Highland Meadows parcel to the northeast and the Highland Park parcel to the southwest. Both tracts have a northern exposure which allows for greater snowpack accumulation, a slower snor{rnelt, and a general ly increased surface and ground -3- water supply than a typical south-facing slope. Several ephemeral drainages incise the site. The drainages in the proposed development portions of the tract are not deeply cut as no appreciable gullying was observed. Ephemeral and perennial springs were observed on and near the site, conmonly in the area of Lots l through 8 in the Highland Meadows portion. The springs generally re- enter the ground surface naturally or by means of man-made conduits and drains. Vegetation on site includes coniferous and aspen trees, ground foliage and grasses typical of a subalpine climate. The area experiences four to six months of snow pac(--per year. Temperatures range from -20 to 50 degrees Fahrenheit in the winter and 40 to 90 degrees in the summer. Present development on sjte jncludes surveyed undeveloped 1ots, paved streets, underground utilities and an underdrain system. The extent and outfall location of the underdrain system are shown on Figure 7. Proposed construction includes single to four-p1ex family housing structures and associated overlot grading and landscaping. Addjtional jnfrastructure development may include: an upgraded underdrajn system, a careful ly planned positive surface drainage system, permanent earth retaining structures, and other structures necessary for proper site development. Geologic Setting The geologic setting of the subject area js complex with many different geologic processes control ling the present site conditions. These processes include: marine and non-marine deposition, uplift, faulting, folding, glacia- tion, glacial deposition, mass wasting, and erosion processes. The geologic investigation included research of published literature, field reconnaisance of the area surrounding the subject parcel , our previous experience in this and similar areas, and on-site geologic field mapping and drilling progrdn with four exploration holes into the bedrock in each subdivi- -4- sion and 17 test holes to a depth of approximately 25 feet. For the majority of the geologic investigation, it was necessary to correlate site specific data with the nore generalized regional information to form a site model. Bedrock Geology Out crops of bedrock were not observed within the boundaries of the subject parcel . The bedrock unit jmmediately underlying the study area is the Minturn Formation, cunposed of grit, sandstone, conglomerate and shale with mjnor dolomite/l imestone beds. The estimated thickness of the Minturn Formation beneath the site is approximately 3000 feet. Underlying the Minturn in the study area is the Pennsylvanian Belden Formation of similar composition, and a sequence of early Paleozoic sedimentary rocks overlying Precanbri an crystal l ine rocks composed of granites, gneisses, and schists. The subject parcel overlies Clastic Units D and E of the Minturn, approx- imately in the middle of the formation. These bedrock units are composed of interbedded and interlensed coarse, poorly sorted micaceous quartzose arkosic sandstones and conglomerates with micaceous sjltstones and shales. The sand- stones and conglomerates are friable to firmly cemented (carbonate) and weather to 'l ight brown or gray. The dolomitic sandstone is medium to coarse grained, angular to subangular, micaceous, arkosic and oxid'ized in part. The clastic rocks are general ly devoid of smal I scale bedding structure and are iointed by moderate to high angle fractures. The sandstone is light gray and weathers to a light orange- brown due to iron oxidation. The micaceous shale is slightly fossilferous and carbonaceous, with thin beds and crossbeds of fine grained sand and silt. The fine grained rocks are moderately indurated, but fracture easily along micaceous bedding planes. -5- Many fractures occurring at high angles to the bedding planes have been filled with a carbonate cement. Some mineralization has occurred resulting in deposits of iron sulfides and oxides. The Minturn Formation dips at approximately 15 degrees to the north north- east in the vicinity of Highland Meadows. The site is located on the western flank of the Vail Syncline. The Vail Syncline is a relatively shallow north trending syncline, which p1 unges toward the center from its northern and south- ern axial extent. The structure is exposed along the sides of the Gore Creek Val ley as it transects the va1 1ey at Vajl. The western flank of the syncline is the homoclinal eastern flank of the Sawatch Anticline of the Sawatch mountain r ange . At least two east-west trending normal faults have been mapped by Tweto in the bedrock units under and adjacent to the subject site. Tweto suggests that these faults orginated in Precambrjan time and were last act'ive in Laramide time; the last mountain building tectonic period that formed the present Rocky Mountains. A smal 1 , probably inactjve normal faul t was fi el d ident ified, exposed outside of the southwestern boundary of the site. This fault appears to strike east and dips steeply to the north. Sample recovery from exploratory hole HM-4 at a depth of 44.5 feet to 69.4 feet (total depth) suggests the possibility of another fault. Samples appear to be disturbed, displ aced, weathered greenish gray micaceous shale. The convoluted appearance of the shale is similar to a fault gouge material although possible displacement by gravity mass wasting of bedrock materials (Iandsl ide) cannot be ruled out. Tweto suggests that fault zones in the area can be tens to hundreds of feet wide. The bedrock faulting on-site has been covered by Quaternary overburden deposits which presently evidence no displacement frsn bedrock faulting. -6- The Gore Fault, wtrich bounds the west side of the Gore Range is likely the only potentially active fault near the site. The Gore Fault is a northvlest trending, southwest dipping, nearly vertical normal fault zone and js located more than four mjles northeast of the subject site. Miocene age displacement has been noted along the northern extent of the fault zone. Quaternary (recent) movement has not been documented. The site is within the Northern Rio Grande Rift seismotectonic subprovince, (Kirkham and Rogers, 1981 ). |',lithin this subprovince, a maximum credible earthquake magnitude of 6 to 7 on the Modifed Mercalli Scale can be expected. Fracturi ng within the bedrock mass appears to be both paral 1el to and at high angles to the bedding. The bedding plane fractures are probably caused by overburden pressure release from glacial and erosional processes and possibly structural extension associated with local faulting. High angle fractures within the sandstone are rough and open, and within the shale are smooth and often fil led with carbonate cement. The high angle fractures are probably caused by structural release associated with 'l ocal faulting. Surf icial Deposits and Geomorphology Surfjcial deposition on-site can be linked to a serjes of geomorphic processes including glaciation, slope failure, alluvial and col luvial processes and the ongoing weathering and erosional processes. At least two glacial stades affected the area during the Plejstocene Epoch; the first, known as the Pre-Bull Lake age and the second, the Bull Lake glacial age. The blankets of glacial debris high on the Gore Creek val 1ey wa1 1s, above Bull Lake deposits, suggest the Pre-Bull Lake glaciation was more extensive than any other glacial period. This glacial stade probably eroded a large "U" shaped valley at Vail. The first stade of the Bull Lake glacial age deposited a lateral moraine at the present site. Samples recovered fron exploration holes suggest that morainal -7- deposition was as high as 200 feet above the present va1 ley floor. Bull Lake glacial till .is a conglomerate of large igneous, metamorphic and sedimentary boulders within a matrix of claley sands and gravels. Deposits are poorly sorted, medium dense to dense and moist to wet. Ongoing erosjon from subsequent less significant glacial stades has eroded much of this lateral morain within the va1 1ey. After the Bull Lake glacial erosion and deposition, evidence suggests that a landslide occurred wjthin the overburden above the site due to glacial oversteepenilrg of previous deposits. Th is sl ide deposited material on the present site and probably northward into the Gore Creek val 1ey. The subject site is entirely underlain by this landslide complex as mapped by Tweto (1977). This sl ide deposit includes very sandy, silty clays and clayey sands with scattered gravels and a few cobbles and boulders. Deposits of clean to slightly silty and clayey sands and gravels wjth cobbles suggest that Gore Creek may have crossed the subject parcel . As Gore Creek meandered across the valley, it downcut through the sl ide mass to its present location. This downcutting preserved a portion of the glacial deposit and the overlying s1 ide mass which is the Highland Meadows terrace observed today. Recent colluvia'l and al luvial deposition appears to have added little to the present terrace. Evidence of old minor slope failures can be observed on the steeper slopes along the terrace notably in the extreme northern parts of Lots 19 through 24, Highland Meadows. This suggests a lack of resistance of these slopes to the ongoing erosjonal processes and a potentjal for future instability. Hydrol ogy In the subject area, surface water and ground water are in great abundance and very interactive as evidenced by the number of spring and seeps. Ground water is located in two zones. The first zone js located withjn the glacial -8- till. This zone carries the permanent ground water table and is confined below by bedrock and above by the less permeable slide mass. Thjs ground lrater zone appears to have a piezometric head ranging up to 30 feet. At exploration hole HM-4 this zone was tapped at a depth of 21.0 to 44.0 feet and produced a surface artersian flow in excess of 1.0 ga1 lons per minute at a surface stand of 18 inches as measured in June, 1983. 0ther exploration holes penetrating this ground water table do not produce a piezometrjc head sufficient to cause a surface flow. The area of recharge for this zone is upslope of the site. The zone of discharge is probably below the site in the Gore Creek valley. From observation of the flow at HM-4, seasonal fluctuation of this ground water table appears to be slight to moderate. A second, near-surface, perched ground water zone is found within the slide mass. The flow in this zone appears to fluctuate tvith the seasons. This zone is caused by infiltration of snow melt and precipitation into the surface soils during the spring of the year. Infiltratjon causes seasonal saturation of the vadose zone and contact and depression spri ngs and seeps. Recharge of this zone is on and directly upslope from the site, discharge is on the downslope of the site. Surface water hydraulics and runoff are compf icated by the number of springs and seeps. Many springs and seeps reinfiltrate the surface a short distance after they emerge. The upslope drainage area is smalI and drainages are poorly defined, indicating a minimal risk of flash flooding on the site. Upslope infiltration and downslope seepage accounts for the majority of the surface water found on site. Geologic Surrnary The site is underlain by the Pennsylvanian age Minturn Formation. This bedrock unit includes dolomitic to arkosjc sandstones and carbonaceous, mica- -9- ceous dark gray shales. Bedrock dips at a 1ow angle to the northeast. A steeply dipping normal fault borders the site to the southwest. Another fault is suspected to transect the site near its southern boundary. Eoth are present- ly inactive. The closest active fault is the Gore Fault 1ying approximately four miles to the northeast. Maximum credible earthquake magnitudes wtrich may effect the site are on the order of 6 to 7 on the Modified Mercal Ii scale. Two glacial episodes appear to have affected the present topography. The first was an erosional sequence creating a terraced concave slope under the present site. The second was a depositional sequence leaving a bench of till made up of large boulders within a gravel , sand and clay matrix. After an erosjonal period, a sl jde occurred above the site depositing sl jde debris across the site. This debris is a sand-clay mixture with some gravels. Gore Creek may have crossed the site for a period before it moved toward the center of the va1 ley and down-cut to its present 1eve1 , leaving the terrace that is now H ighl and Meadows . The Highl and l'leadows terrace is poorly drained of precipitation and snow melt; many springs and seeps can be observed. These seeps suggest seasonal1y saturated soils and high or perched ground water conditions. They are probably associated with the small slope failures that can be seen along the steeper areas near the southern boundaries of the site. Geologic Hazards Bedrock dips gently to the northeast and the ground slope is to the northeast. There are relatively weak shale beds within the rock and many fractures, paral lel and perpendicular to the bedding planes. These conditions tend to weaken the overall rock mass although the reduction in strength is not considered significant to allow for massive slope failure within the bedrock units. Solution cavities, karst topography and related surface subsidence -10- are often associated with carbonate rocks similar to those within the Minturn Fonnation. No evidence of these features were found during our investigation, although the potential for their existence is possible from our experiences in the area. Subsoils on site consist of three basic groups: Glacial til1, canprised of boulders and cobbles in a matrix of gravel , sand and clay (Unified Soil Classification GP/GW/GC); Sl ide mass, comprised of sand-clay with gravels (CLISC); and Alluvium, comprised of sand and gravel with cobbles and some clay (SM/ML). The glacial till general 1y occurs at a depth below the surface of greater than 20 feet. Present hydrologic conditions across much of the site present impor- tant constrajnts to development. These conditions include seasonal ly high ground water, and seeps and springs resulting in saturated surface and subsur- face cond itions. There were no actjve faults identified on or in close proximity to the site. The site lies within the northern Rio Grande Rift subprovince which suggests a max'imum credible earthquake magnitude of 6 to 7 on the Modified Mercal 1i Scale; this correlates to a seismjc acceleration of approximately 0.07 times the acceleration of gravity (0.079). The most obvious geolog ic hazard associated with the Highl and Meadows Terrace is the stability of the steeper slopes. The strength of the surficial deposits available for resisting failure js re1 atively smal 1, particularly when saturated. The shear strength of the underlying glacial till is significantly more than the surficial deposits although the possibil ity of failure stil l exists. The strength and orientation of the bedrock units appear to present only a very minor hazard. Solifluction is the slow downward movement of fine grained surficjal soils -11- due to the loss of shear strength resulting from excess pore water pressure during seasonal freeze and thaw. No evidence of solifluction was observed during our field investigation a1 though it has been proposed by others in previous investigations that the potential for solifluction exists on site. Solifluction is not considered a significant hazard once proper surface and subsurface drainage is implemented. It could potential 1y be a hazard for developed properties adjacent to undeveloped properties which are not properly dra ined . Although an economic mineral eval uation investigation, no economic mineral deposits any anticipated at depth. No evidence of site and consequent'ly, no subsidence hazard is thought to exist. was outside the scooe of th is were observed on site nor are previous mining was observed on due to underground mine workings DATA ACQUISITION A program of field and laboratory investigation was implemented to recover samples for geologic interpretation, c'l assification and laboratory testing in order to evaluate the physical properties of the pertinent subsurface materi als. In addition, slope inclinometer casings were installed and baseline readings were obtained to provide a means and reference for'long-tenn monitori ng of slope movernents. Details of the data acquisition phase of this study are discussed in the following paragraphs. Field Investigat ion The field investigation consisted of drilling one test hole on each lot included in the study. Approximate locations are shown on Figures lA and 1C for H'ighland Meadows and Highland Park, respectively. 0f the 25 test holes dril led, 17 were drilled to a depth of 25 feet. The rest were drilled various depths -12- For the 'into bedrock. Both disturbed (California and Standard sp1 jt-barre'l ) and undis- turbed (thin-wall tube) samples were taken in overburden soils; rock cores were taken in bedrock. Logs of the borings depicting subsurface stratigraphy, types and depths of samples, ground water data and penetration test results are presented on the Logs of Test Holes, Figures A1-1 and A2-1 . Individual logs for the deeper test holes are presented on the Logs of [xploration Holes, Figures AL-2 to A1-9 and A2-2 to A2-8. The test holes were approximately located in the field by tape and compass. several 'lots, the services of a bulldozer were required to gain access to test hole locat ions. Ground water measurements were made on the dates indicated on the test hole 1ogs. These measurements pertain to the dates taken and may not reflect fluctu- ations in the ground water due to changes in season or weather condjtions. Laboratory Testing A series of laboratory tests were peformed on representative samples recovered from the various strata to determine their classification, shear strength and settlement/heave potential . The resu'l ts of these tests are summar- 'i zed on Tables 41-10 and A2-9 and specific test results are presented as Figures A1-11 to Al-19 and Figures A2-10 to A2-i5. The applicable shear strength parameters for the stability analysis were based on field penetratjon test results and laboratory unconfined and triaxial compression testing. The presence of large gravels, cobbles and in some cases boulders in the upper clay stratum made sampling very difficult and resulted in a limited number of testable samples. Further, the presence of the gravels and cobbles tended to djstort the field penetration test results, making the soils appear stronger than they were. Therefore, final selection of the parameters used to model the subsurface strata was based to a large extent on experience, -13- engineering judgement and on-site case histories as well as the actual test data. The slope stabil ity analysis was based on the following parametric model: Colluvium 750 0 130 Glacial Till Bedrock Cohesion, psf Internal Friction, degrees Total Unit tJeight, psf Slope Inc l inometers 500 34 130 0 48 155 Slope inclinometer casings were installed in the four deep test holes in Highland Meadows and in test hole HP-2 in Highland Park. The test holes on these lots were located so as to avojd construction areas in order to protect the relatively easily damaged PVC casings. The purpose of these casings is to permit long-term monitoring of slope movements. Long-term monitoring of the slopes is beyond the scope of this study, however, baseline (initia1 ) readings of the casings were made for the those located in Highland Meadows. The casing installed in test hole HP-2 in Highland Park is longer than our present equip- ment could measure (120 feet versus 100 feet), so no base1 ine reading is inclu- ded. The baseline reading for this casing can be taken at any time, but prefer- ably before any construction. The field data for the baseline readings were taken on July 14, 1983 and are presented as Figures A1-20 to A1-23. l.le are avajlable to discuss a long- term program for monitoring slope movements. GEOTECHNICAL CONSIDERATIONS General The design of all structures should cons iderat ions. Any I oad i ngs appl i ed to stress state which exceeds the allowable include several geotechnical-related the subsoils should not create a shear strength with an appropriate -14- factor of safety. This applies to stresses imposed by construction of embank- ments as well as those due to foundations. The short and long-term stability of excavations, walls and slopes should have a reasonable factor of safety with respect to both local and regional failure. Provisions should be made in the design for the possible detrimental effects of surface and ground water on the structure, its foundations, retaining structures or overal 1 stabil ity. Finally, any movements of imposed on the structure by settlement or heaving of the subsoils should be within tolerable limits. In addition to the geotechnical considerations, the viabil ity of the project should be analyzed with respect to the geologic conditions present and the geologic processes affecting the site. This is of particular importance when dealing with mountainside property. As discussed in the preceeding geology section, the processes of weathering, erosion and landsl iding are gradual ly moving the overburden soils and bedrock downward to the valley below. These factors were considered on both a local (site-specific) and regional basis in order to develop the conclusions and recornmendations contained in this report. Literature Review A review was made of avaiiable literature concerning primarily the land- sl iding phenornenon associated with this study. Conclusions drawn from this review were used to develop the methodology for analyzing slope stabjlity of the areas jnvestigated. A bjbliography of those works which were considered of the most significant to this study are ljsted in the appendix. Several key points were noted in this review which helped govern the analytical approach. These points are discussed in the following paragraphs. Natural slopes, as opposed to man-made embankment slopes, typical ly exhib'i t a far more varied set of subsurface conditions. The result of this is that no amount of subsurface investigation is detailed enough to develop -15- soil parameters for which there is a high degree of certainty. Consequently, some sort of averaging technique or a range of values must be used. l.lhen this is done, jt becomes more diffjcult to identify those areas which are more likely to have problems. The lack of homogeneity in the subsurface cond'i tions leads to another problem in analyzing natural slopes. That is, the analytical method used to analyze slopes require that the subsurface conditions be idealized. In the case of man-made slopes, this can be done with a high degree of accuracy. In the case of natural slopes, however, such ideal izations tend to considerably oversimplify the subsurface conditions. The analytical method is then limited by the accuracy of the data which jt is processing. Numerous problems are also encountered in evaluating the soil parame- ters themselves. Studies have shown that failures of natural slooes can best be modeled using the residual shear strength for the subsoils. Therefore, the normal laboratory shear strength determinations, which are based on peak shear strength, will tend to overestimate the stability of a natural s1ope. In addi- tion, most natural slopes on mountainsides contain colluvial or landslide deposits which contain a significant secondary structure. The failure planes comprising this secondary structure, are generally not encountered during the sampling process, and are not present in the samples that are normally tested in the laboratory. Again the soils shear strength at failure tends to be overes- t imated. Another factor that separates natural slopes from man-made slopes, is the control over geometry. Man-made slopes can be designed to have a njnimum factor of safety present for any zone within the cross-section. Natural slopes, however, generally have an irregular cross-section and certain areas may have a much lower stability than others. This could create the potential for a pro- -16- gressive failure as the less stable areas fail first resulting in a change in the geometry of the slopes and thereby decreasing the stability of other areas. This progressive failure sequence could be of particular significance in ter- raced areas where steep slopes are separated by flatter slopes. Several authors agree that the design of structures on natural sl opes should be governed by higher minimum factors of safety than for man-made slopes. This is primarily to allow for a greater variability in subsurface conditions including the presence of secondary structure, limits of the analyt- ical methods used and difficulty in obtaining representative samples for labor- atory testing. Method of Analysis Based on the objectives of this study, the literature reviewed, the results of the field and laboratory investigations, and the results of other studies performed in this area, a method of analysis was developed to evaluate the complex slope and subsurface conditions that are present. The analytical tool used in this method of analysjs is the method of slices, slope stability computation method utiljzing a circular failure surface and the Modified Bishop method for resolution of forces. 0bservation of several slooe failures in the vicinity of the project area indicate that a circular failure surface is valid. A significant slope failure of this nature was observed on Lot 22, Highland Meadows Filing 1. As discussed be1ow, this failure was used to help model the subsurface strength parameters for the analysis in other areas. The results of a slope stability analysis using a circular failure surface are presented in terms of factors of safety. The factor of safety is the ratio between those forces tendjng to prevent fajlure and those forces tending to cause failure. A simplified depiction of this method js shown in Figure 2A - Rotational Slope Failure. The forces tending to resist failure are essential ly -L7 - the soil shear stresses along the failure surface. The weight of soil within the failure surface canprises those forces tending to cause failure. Al 1 points along the ground surface above the failure surface are representated by the factor of safety pertaining to that arc. The type of failure described above (i.e., affecting the original ground surface), js called a 'first event failure'. After the appearance of a first event fa il ure, the ground surface is redefined as the soi l sl ides down the s1ope. This redefjned ground surface must also be checked for stability. A failure occurring in this redefined slope is termed a 'progressive faiiure'. Oepending upon the soil parameters and geometry of the slope, a series of progressive failures could be jn'i tiated by the fjrst event, even if the up or down slope geometry initially had a much higher factor of safety. A graphical depiction of a typical progressive failure sequence is shown in Figure 28. Our field investigation revealed that two types of slope failures are occurring in and surrounding the project area. The most common js exhibited jn slumping road cuts. These cuts have typical 1y been constructed to 1.5 horizontal to 1.0 vertical slopes (1.5 H:1.0 V) A1 I the slumps whjch were observed exhjbited two significant conditions. First, the subsoils were gener- a1 1y more granular than the surficial clays which typjfy most of the area. These granular sojls consisted of silts and fjne sands. Second, ground water flow was noted in all of these granular zones. Based on our observations, these granular zones tend to occur in pockets and/or lenses and are general 1y limited to the upper five feet of the subsurface materjals. The other type of fajlure which is less evident but far more serious, is the deep-seated failure. This type of failure is a function primarily of the shear strength of the clay layer and is not influenced significantly by the water bearing granular lenses. These deep-seated failures may have failure -18- arcs as long as several hundred feet and as such were analyzed on a regional basis. That is, they do not necessari Iy begin or end at the established lot lines. To develop parameters that could be used in the slope stability analyses, the results of the laboratory tests were used for some prel iminary slope stabil ity calculations. The soil parameters were then adjusted to force a factor or safety of 1.0 to represent areas of known failures. Two areas in particular were used to develop a parametric model; the recent rotational failure on Lot 22 Highlands Meadows Filing 1, and the previously mapped land- sljde area in the central portion of Highland Park. The parameters developed in this manner were then used for regional stability calculations for both areas. This procedure resulted in very little modification of the laboratory results. 0ne limjtation of this study, or any study, that is performed over a finite length of time, is the sensjtivity of the shear strength of the clay soil to its degree of saturation. Since a clay soil exhibits a higher strength when it is dry than when it is wet, the relative stability of a clay siope can vary greatly between wet periods and dry periods. At the time this study was performed, relatively vvet conditions prevailed. In fact, recent field reconnaissance trips indicated that very ljttle drying out of the subsurface clays occurred during the sumrner of 1983. Therefore, further softening of the clays could result from this contjnued period of saturation, and continued reduction of the shear strength of the clays could result in less stable slopes in the future. Based on discussions with persons familiar with the project area, the spring and summer of 1983 exhibited unusually wet conditions. As a result, we believe that the results of this study represent conditions judged to be the worst in recent years. However, another wet spring and summer could result in even less stable slopes just as a dry winter and spring could result -19- in improved conditions. ENGINEERING ANALYSIS General Since design details such as site specific topography, proposed building footprints, proposed grading plans, and retaining wa1 1 designs were not avail- able at the time of thjs study, our conclusions and reco{nmendations have ne- cessarily been generalized. More specific recommendations can be developed once the design details are known. Reqional Slope Stabil ity It is the conclusion of this study that regional slope stability is the most important factor affecting development. 0ther geotechnical-related aspects of design such as foundation design, basements, minor road cuts, and drainage can be mitigated by conventional , cost-effective construction methods. The potential exists for the occurrence of regional slope failures that may affect more than one lot or may be so 'l arge that practical mitigative measures do not exjst. Such occurrences present the only hazard we have found that would preclude development of some lots. The other hazards we have identified can, in our opinion, be mjtigated at reasonable cost. Factors of safety were computed for the characteristjc slope and subsurface conditions as described jn the method of analysis. For the earthquake analysis, an acceleration of 0.07g was used. Hazard areas tvere then plotted for the lots jnvolved wjth thjs study in accordance with the classification scheme described below (See Figure 4). Hazard Area Cl assif icat ions Reg ional slope stabil ity-re1 ated hazard categories of rjsk. These are denoted by areas were classified using five the letters 'A' through 'E'. The -20- degree of risk in subjective terms associated with each class together with the classification criteria are shown on Table 1, Hazard Area Classification System. Since the Class 'C' areas are on the borderline between moderate risk and very high risk slopes, they are further descrjbed by a subscript indicating the critical failure mode. In the case of Class 'CB', insufficient subsurface data was available to determine if these areas would better be classed as 'B' or 'D'. Additional field investigation would be required to determine its final classification. The hazard areas are shown on Fiqure 4. Table I - Hazard Area Classification System Fi rst E art h-Class Deqree of Risk Event quake A B (' D E Note: LOW Moderate High (Condit ional ) Very High Unst ab I e >2.5 >2.0 >1 .5 >1.i <i .1 and an0 an0 an0 or >2.0 >i.5 >L.2 >i .1 <1.1 an0 and an0 and or >z .0 >i .5 >L.2 >1.0 <1.0 Hazard Area(s) Class'C' are conditional .( i.e. could be re-classified a either'B'and'D'pending additional study) and are depicted with a subscript to jndicate which mode of failure governs it. Critical Modes for Class 'C' Areas Cg - Dependent Cp - Critical Cp - Critical CE - Critical Surface llater and Ground Hater on depth to bedrock mode is first event mode js progressive failure mode is earthquake event As discussed in other reports prepared for water has a considerable impact on the stability cohesive soils (clays), increased moisture results For granular soils (sands and silts), the presence the Highl and of slopes. in a loss of of a ground Meadows area, In the case of shear strength. water table and Computed Factor of Safety -?L- corresponding hydrostatic pressure causes a reduction jn shear strength. It should be noted that a hydrostatic pressure by itself does not cause a strength reduction in purely cohesive soils, rather, this reduction js a result of the physiochemical action of the moisture on the c1ay. The two sources of water to the site are rainfall and snowmelt. All water initial 1y begins as surface water wjth some percolating into the subsur- face to fonn various ground water conditions. The percolation of water contri - butes to an increase jn moisture content of the subsoils. In clay soils which percolate very slowly, the moisture may be retained for a very long time. Granular soils percolate much more rapidly, and if they are significant in thickness and extent, a ground water table may develop. Since the flow in these layers js re1 atively rapid, they are majntajned only as long as there is a recharge. 0nce rainfall and snowmelt are no longer supplying recharge, the layers begin to dewater and drain the adjacent c1ays. This causes a reduction in soil moisture and increase in strength of the c1ays. The strength of the c lays can be f urtherimproved during the summer by dry, sunny weather. During a normal weather year, spring snowmel t and rains contribute to softening of the subsoils and the development of springs. By the end of the summer the springs typically dry up and the subsoils harden somewhat. This recent year, a thick snowpack together with high spring and summer rainfall has prevented drying of the spri ngs and subsoils. This suggests that even a normal weather pattern for the next year could result in both softer subsoils and greater flow jn the springs. To reverse this trend, an unusually dry year would probably be required. Mitigative measures are avajlable to control the damaging effects of water. Unfortunately, the only way to stop percolation would be to seal the ground surface with an impermeable liner. This is not practical frsn a number -22- of standpoints includjng aesthetics, cost, and the fact that areas well beyond established property lines would have to be sealed. As a result, there is little chance of being able to significantly affect the moisture content and, therefore, the strength of clay subsojls. The shallow granular layers, however, can be dewatered by a system of underdrajns. While these underdrains would not appreciably improve regional stability, they would have a positive effect on fail ures of shal low cuts resulting from hydrostatic pressures in granul ar layers. Peripheral foundation underdrains would help minimize infiltration of water into foundation subsoil s and help control foundation settlement and maintain bearing capacity. It cannot be over-emphasized that the installation of underdrains cannot be counted on to cause a significant improvement in the shear strength of the clay subsoils. Therefore, they would be expected to have litt'le impact on the reg ional stab i I ity. E arthwork The amount of earthwork that can be accomplished at the site js l imited to a'l arge degree by the presence of the roads. Therefore, only on-1ot grading will be considered. Both cutting and fil'l ing will tend to decrease the stabil- ity of slopes jn the high ri sk areas (Classes'C', 'D', and'E'). In the lower risk areas ('A' and 'B'), minor cutting and fil ling wilI be allowed with careful design. Use of basements and retaining wa1 ls wil I similarly increase the hazard in high risk areas. The fo llowing mitigative measures should be considered in developing grading plans for individual lots: 1. Re-grading should be limjted to lower risk areas (Classes A and B). 2. Step first f'loors to conform to existing grades. 3. Protect the ground surface from erosion, particularly on steeper slopes, -23- minimizing remova'l of existing trees and vegetation. 4, Minimize the depths of cuts and fills and use the flattest possible slopes. 5. Expect some local sloughing of slopes and be prepared to immediately repair slopes that slough. 6. Minimize the use and height of retaining wal 1s. Be advised that a retaining wall, while jncreasing local stability, may at the same time decrease regional stabil ity. Al I retaining wa1 ls should be analyzed individual ly for their impacts on regional stabil ity and development of design criteria. Found at i ons Foundations for the proposed structures may be designed as shallow spread foot'ings. The depth below ground surface of the foundation should be determined during examination of the excavation by a geotechnical engineer. As a minimum, foundations should be p1 aced below the zone of frost penetration for the Vail area (48 inches). Al lowable footing bearing pressure recommendations are contained in the 1ot-specific recornmendations in a following section. In some cases, it may be necessary to revise the recunmended beari ng pressure based on field cond itions at the time of construct ion. Footings should be placed on a relatively dry, compacted subgrade to minimize foundation settlement. In wet areas, this may require construction dewatering or installation of the foundation drains before pouring the footings. Subgrade soils wtrich become loosened during excavation should be reccrnpacted. Footings constructed in accordance wjth these recommedations should experience settlement within the tolerable range of the structures. Deta i led Recommendations Detajled eng ineering recommendations are contained in subsequent sections of this report. The first of these sections "General Recornmendations", dis- cusses those items that pertain to all lots and the study area as a whole. The -24- next section, "Lot-Specific Reccmmendations" deals wjth those recornmendations that are peculiar to each lot. PLAN REVIEl.l AND CONSTRUCTION INSPECTION This report is the first step in a comprehensive effort to properly engi- neer the proposed structures from a sojl and foundation standpoint. The recom- mendations contained herein are considered 'prel iminary design criterja' and they become'final' only when incorporated in the design plans and specifica- tions and are properly implemented during construction. In the case of the marginal areas identified herein (StabiIity Classification 'C'), additional stud'ies wil I be required to develop pref iminary design cri teria. The design p1 ans and specifications should be reviewed by Fox & Associates to accornpl ish the following purposes: 1. Determjne if the prel iminary design criteria have been properly incorporated into the design concept and construction documents. 2. Determine if the preliminary design cri teria address alI of the proposed design fea-tures. If not, additional studies may be recommended. 3. Develop design criteria on an individual basis for earth retaining structures. 4. Develop a plan for construction observation of soil and foundation-related i tems . 5. Determine if the proposed construction has any detrimental effects on other properties and recqnmend alternative solutions, if warranted. Ideal 1y, this review should take p1 ace well in advance of the start of construction to permit sufficient time for a thorough review and implementation of any changes that may be necessary. During the construction phase, Fox & Associates should be cal led to observe construction of the soil and foundation-related work to determine -25- if our recommendations have been properly executed. Specific jtems of construc- tion that should be observed include, as a minimum: 1. Earthwork 2. Foundation subgrade 3. Slab-on-grade, sjdewalk and driveway subgrades 4. Backfil l of trenches and walls 5. Underdrain instal lation RISK General The notion of risk is an important aspect of any geotechnical investiga- tion. The primary reason for this is that the investigative and analytical methods used to develop geotechnical recornmendations do not comprise an exact science. The analytical too'l s which are used are generally emperical and must be tempered by engineering judgement and experience. Therefore, the solutions or recommendations presented in any geotechnical study should not be considered rjsk-free and more importantly, are not a guarantee that the proposed structure wilI perform satisfactorily. lrJhat the engineering recommendations do constitute, is the geotechnical engineers' best estimate of those measures that are nec- essary to make the structure perform satisfactorily based on usually limited subsurface jnformation. The purpose of the following paragraphs js to discuss the concept of risk so the owner, who must ultimately decide what is an accep- table risk, can better apply the fjndings of this study. Factor of Safety As discussed above, the most critical geotechnical consequence of this study is considered to be regional slope stabiljty. The stabil ity of a portion of this slope is expressed as a factory of safety. It js important to note that -26- the concept of factor of safety is a derived value and not an intrinsjc property of the slope. The accuracy with which the factor of safety for a given slope can be determined, is based on a number of factors the most significant of which are listed below: 1. Vari abil ity in surface conditions. 2, Variabjl ity and type of subsurface conditions. 3. Va1 idity of the analytical method. 4, Va1 id ity of simpl ifying assumptions. 5. Intensity of study. 6. Certainty of the des ign load ing cond ition occurring. Depending on how well the above factors can be assessed determines what rninimum factor of safety would be required to have a reasonable degree of confidence that a fajlure wjl'l not occur. It js the geotechnical engineers' responsibility to assess these conditions and advise the owner as to a minimum acceptable factor of safety. Probabi l ity of Fa il ure Theoretical1y, a factor of safety of 1.0 indicates that a slope is on the verge of instabil ity. Therefore, any lower factor of safety should result in failure and any higher factor of safety should theoretical ly represent a safe slope. Horvever, due to the uncertainty and the factors discussed in the preceeding paragraph, all slopes, even those with factors of safety greater than 1.0, have some potential for fajlure. The higher the computed factor of safety is for a given slope, the lower its probabil ity of failure will be. In recent years, approaches have been developed to relate computed factory of safety to probabiIity of failure. This approach is cal led a 'probabil istic ana'lysis' and can be performed at a relatively great expense. 41 though such an analysis was beyond the scope of this project, it is beljeved that the concept -27 - of a probabilistic analysis of fajlure is very important. An example of the relationship between computed factor of safety and probability of failure is presented on Figure 3, Ideal ized Probabil istic Distrjbution. This figure indicates two curves representing the results of probab'i Iistic analyses for two different slopes. 0n this example, a factor of safety of 2.5 was used to show the difference between Curve A and Curve B. For the site represented by Curve A, a factor of safety of ?.5 wou'l d result in a probability of failure of about 1 in 8. However, for the site represented by Curve B, a factor of safety of 2.5 would result in a probability failure of about I in 2000. This illus- trates graphically that the value of factor of safety cannot be considered jn absolute terms. For the slope represented by Curve A, a much higher minimum factor of safety would be required to provide a reasonable degree of safety than for the site represented by Curve B. It should be emphasjzed that the data in Figure 3 js for jllustratjon purposes only and was not based on data from this project. Intensity of Study The relatively large areal extent of the project site was investigated by 25 widely-spaced borings. Because of the limited data that was available to perform this study, the subsurface conditions between boring locatjons had to be based primarily on geolog ic 'i nterpretation. As noted above, consjderable variation in the subsurface conditjons was encountered. It is our opinion that the intensity of the study, despite the widely spaced nature of the borings, for the most part tvas sufficient. However, the recommendations for some areas could be refined significantly if more subsurface information were available. Those areas where additjonal study could possibly be beneficial are discussed in the recommendations section of thjs report. -28- Cost-effectiveness of Solutions The safety, and therefore the potential risk, of a particular slope js inversely proportional to the cost of development. The probability of failure can be reduced by spending more money on mitigative measures. However, exper- ience has shown that there is a practical limit to the amount of money that can be spent on mitigating potential slope problems, usually resulting in a tradeoff betlreen development costs and degree of safety. The recornmendations contained in this report deal primarily with those solutions which are considered to have a reasonable cost associated with them. It is possible that other more exotic and much more costly solutjons may be available to solve some of the slope problems, however, these are beyond the scope of this particular study. Such solutions could be evaluated in more detail in subsequent studies. GENERAL RECOMMENDATIONS The recommendatjons contained in this section are appl icable to all lots within the study area; both for Highland Meadows Filing No. 1, and Highland Park. In additjon, lot-specific recommendations are presented ind ividual ly in the following sections that supplement the general reccrnmendations to reflect individual lot conditions. The engineering and construction for a given lot should be governed by both the general and 1ot-specific reccrnmendations. Regional S'lopes As discussed above, regional slope stability is the one factor which can preclude development of a specjfjc area. The recsnmendations below are based on the conclusions of this study and our opinion regarding what should be a reasonable degree of risk for the type of development proposed, the location of the site and the potential dangers if a major slope failure were to occur. Ultimately, the decision of wtrat degree of risk is acceptable must be made by -29- the owner in accordance with the policies and regulations of applicable govern- ing entities. Our recqnmendations are as follows: At. Construction, including grading should be limited to only those areas c lass ified as rA' or 'B' . A2. Areas class ified as 'Cp' or 'CF' have the potential for being reclass- ified as 'B' if additional studies are made. There is no quarantee that additional study will result in a reclassifjcat'ion. A3. Areas classified as'CB'have a potential for being reclassjfied as'B' jf additional test borings or probes confirm that the bedrock is relatively shallow over a wide area. Again, there js no guarantee thjs wjll be the case. A4. The regional underdrain system should be expanded to: (a) intercept springs in granular layers; (b) minimjze the saturation of clay subsoils to curtail their loss of shear strength; and (c) reduce the potential for slope failures in minor cuts. A5. Retaining walls are not consjdered a feasible means for m'i tigating regional stabj lity problems. A6. If any regional slope failures do occur, either on improved or unimproved properties, they should be investigated immediately to assess the potential impacts on other properties, particularly regarding progressive failures, and to develop remedies. Local Slopes The recommendations in this section deal with the stability of mjnor cuts for driveways, regrading of lots and the slope of the existing road embank- ments. lle recommend the following: 81. Existing road cuts on a 1.5H (horizontal) to 1.0V (vertical) slope will generally be stable where no springs or granular'l ayers are present. -30- 82. Hhere granular layers or springs are present, some 1.5H:1.0V cut slopes could be.expected to fail. Although this presents some degree of danger, we believe this risk is acceptable sjnce many of the problem areas have already been identified and repaired. Any additional areas that fail should be repaired immediately. 83, Analysis of roadway fjlls was beyond the scope of this study. Any develop- ment should be designed to maintajn the integrity and gecrnetry of the existing fill slopes to insure they will perform as designed. R4. Cuts and fills should be limjted to four feet in height and slopes of 1..5 H : 1.0 V or flatter may be used providing they do encounter spri ngs or granul ar soi l s. Cuts shoul d be inspected by a so il s eng ineer duri n9 construction to identify the soils to determine jf remedjal measures are warranted. Even with these precautions, some sloughing of mjnor slopes may occur. These slopes should be immediately repaired. 85.Retaining wa11s may be used to construct vertical ,'local slopes of limited height. Acceptable retaining wa'l 1 pl acement and height cannot be general- ized in this report and should be analyzed on an individual basis. Dra i nage As discussed above, two types of underdrains are recommended for the project area: (a) a regional drain system to de-water the granular subsurface layers; and (b) perimeter foundation drajns to expedite construction and mini- mize softening of foundation bearing soils. In addition to subsurface drainage, reccrnmendations are also provided for surface drainage of storm runoff and snow mel t. Cl. The existing regional underdrain system should be expanded on lots located to the south of Meadowbrook Drive in Highland Meadows Filing No. l. Additional drains should be located as shown on Figure 7 for maximum -31- c2. effectiveness and should be located as far upslope as possible. Additions to the regional underdrajn system for Highland Park are not proposed at this time pending further investigation of the Class 'C' areas. The maximum depth of the underdrains will be controlled by the elevation of existing drains to allow for sufficient slope to the outlet. The underdrain should have a clean gravel backfjll with filter c'loth and perforated pipe at least four inches in diameter. Perimeter foundation drains should be installed around all structures and should discharge to the existing underdrain system. Typical details of perimeter drajns for fjve anticipated subsurface conditions are presented as Figures 5A through 5E. The detajl(s) expected to be applicable to the specific 'lots are discussed on the Lot-Specific Recornmendations. It should be noted, however, that these details are preliminary and different details may be dictated by actual cond'itions at the time of construction. the conditions for which the underdrain details pertain are summarjzed below; Figure Fi gure Fi gure Figure 5D Figure 5E C3. Drainage of foundation ditching to a sump. If ation of the perimeter cons truct ion. Basement with low ground water. Basement with high ground water Basement with high ground water and soft subgrade Crawl space with low ground water Crawl space with high ground water excavations in most cases can be accomplished by extremely wet conditions are encountered, install- underdrain may be required prior to foundation 5A ER 5C Surface drainage should be designed to direct water away fron the Struc- -32- c4. tures to positively drain each 'lot. Roadside ditches should have adequate capacity and preferably be lined to minimize infiltration. It is also recommended that the ground surface in areas disturbed by construction be seeded or landscaped with decorative rock to reduce erosjon potential. 0verlot Grading t ions D1l Recommendations for overlot grading consist of the preliminary specifica- contained in Appendix B and the following: In general, cuts and fills should be Ijmited to a maximum of four feet. Cuts and fills of greater thickness may be approved for a specific location 'if subsurface conditions warrant. This should be determined durinq final oeslgn. 02. First floors and foundatjons should be stepped to conform to existing grade and minjmize the amount of cutting and filling. In design of stepped foundations, the transfer of shear to framed walls should be avoided (see Recommendations for Basements/Foundation Wa1 1s). D3. Cohesive soils, similar to those found on sjte should be used for all non-contained fjl ls. Fil ls contained by basement, foundation or retaining wa1 1s may be granu'l ar. D4. All fills on s'l opes steeper than 5 horizontal to l vertical should be keyed into the existing slope in accordance with the Benching Detail presented as Figure 6. Foot i ngs El. l,le recommend using continuous or isolated spread footings, designed for a maximum allowable bearing pressure of 1500 psf, for foundation support. E2; Footings shou'l d be founded at least 48 inches below final outside grade for frost protection and should have a minimum width of 18 inches. Interior footings may be placed at shallow depths. -3 3- E3. A'l 1 footings shou'ld be poured on a compact, dry subgrade. Any soiI loosen- ed during excavation should be removed or recanpacted. If necessaryr drainage measures or the use of gravel or stone to replace, soft areas may be required. No footings should be poured until the subgrade has been inspected and approved by a representative of this firm. '84. All interior'load bearing walls should be founded on footings or structural beams. Basements/Foundation I'lal I s Fl. lJe recommend that basements be constructed only in areas classified as'A' for regional slope stability. Construction of basements in areas of higher risk could affect the stability of adjacent areas. Crawl spaces are recsnmended for areas classified as'B'. F2. Foundation/Basement wal ls should be designed in a modul ar fashion to maxjmize lateral rigidity. Concrete slabs and structural floors should be structurally tied to the walls. Downslope walls should be designed high enough to resjst horizontal shear transmitted by the floor frorn the top of the upslope wall. This shear should not be permitted to transfer to a framed wal l. F3. Foundation and basement walls should be designed as retaining wa1 1s with both vert ical and horizontal reinforcing. For prel iminary design, an equivalent fluid earth pressure of 80 pcf is reccrnmended. F4: Foundation or basement walls excavations encountering springs or water bearing granular layers may regu'ire use of a granular backfill to reduce lateral hydrostatic pressures. These conditions should be evaluated on a case by basis to ensure the walls will perform satisfactorily. Floor Sl abs Gl . Slab-on-grade floors may be used for basements provided they are placed on -34- a dry, compact subgrade. Any soils loosened during excavation should be removed qr recqnpacted. G2. tlhere the subgrade for slabs-on-grade is soft, it may be undercut or stabilized with gravel or crushed stone to attain a stable working surface. G3. Floor slabs should be structural 1y tied to foundation walls to maximize lateral rigidity of the structure. G4.' ln high ground water situations, a drainage Iayer of clean gravel should be placed beneath the slab as shown on Figure 5C. LOT.SPEC I F IC RECOMMENDATIONS The general reccrnmendatjons discussed above have been summarized for the individual lots, together with any additional recommendations that are perti- nent. These recommendatjons are presented as a qujck reference only and should not be considered complete unless combined with the general recqnmendations given above. Specific recommendations are not given for those lots that do not have at least a 'Cr regional slope stabil ity classification for at least a port'ion of the lot. -35- Lot No. 1 , Highland Meadows Regional Slope Classification(s): ' B, Cp & D See Figure 4A Maximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Recormended Cut/Fill Slopes: 2.5 H : I V Maximum Cut/Fill Slopes: 1.5 H : 1 V Regional Underdrain: Along south property line, tieing to manhole in Vermont Road (see Figure 7). Anticipated Perimeter Foundation Drain Detail(s): Figure 58 or 5C Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structura'l Fjll: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing |.|idth: 18 inches Applicable for Easement: No Equivalent Fluid Lateral Pressure: 80 pcf The regional stability of this lot is affected by a progressive fai'l ure mode from downslope (across Vermont Road). Additional studies are recommended to evaluate the possibility of re-class ifying the class 'Cp' portion of the lot or developing a scheme for protecting against a progressive failure. tJithout these studies, development is considered high risk. Note: These recommendations are a sumnary only for this specific lot. Refer to "General Recommendations" for canplete details. -36- Lot No. 2 , Highland Meadows Regional Slope Classification(s): A, B & Cp See Figure 48 Maximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Recommended Cut/Fill Slopesz 2.5 H : I V Maximum Cut/Fil1 Slopes: 1.5 H : 1 V Regional Underdrain: Along north and east property lines, see Figure 7. Anticipated Perimeter Foundation Drain Detail(s): Figure 58 or 5C Compaction Requirement - Non Structural Fi'l l: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail : See F'igure 6 Maximum Footing Eearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing l,ljdth: 18 inches Applicable for Basement: YES Equivalent Fluid Latera'l Pressure: 80 pcf Structure should be located in c'l ass 'A' area. Note: These recommendations are a summary only for this specific 1ot. Refer to "General Recqnmendations" for canplete details. -37 - Lot l{o. 3 , Highland Meadows Regional Slope Classification(s):' A, I & Cp See Figure 4C l.laximum Cut Depth: 4 feet l,laximum Fil I Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : I V Maximum Cut/Fil1 Slopes: 1.5 H : I V Regional Underdrain: Along east property line. Anticipated Perimeter Foundation Drain Detail(s): Figure 58 Compaction Requjrement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fil'l: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing l'lidth: 18 inches Applicable for Basement: YES Equivalent Fluid Lateral Pressure: 80 pcf Structure should be located class 'A' area. Note: These recommendations are a summary only for this specific lot. Refer to "General Recqnmendations" for conplete details. -38- Lot No. 4 , Highland l.leadows Regional Slope Classification(s): A, B & CF See Figure 4D Maximum Cut Depth: 4 feet l,laximum Fil I Thickness: 4 feet Recommended Cut/Fi'll Slopes: 2.5 H : I V ilaximum Cut/Fill Slopes: 1.5 H : I V Regional Underdrain: Along east property 'l ine. Anticipated Perimeter Foundatlon Drain Detail(s): Figure 58 Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Itlinimum Footing Depth: 48 inches l'linimum Footing I'lidth: 18 inches Applicable for Basement: YES Equivalent FIuid Lateral Pressure: 80 pcf Structure should be located in class'A'or'Brareas. Additional study is required to locate structure in class 'C' area. l{ote: These recommendations are a summary only for this specific lot. Refer to "General Reccmmendations" for conplete details. Revised January 3, 1984. -39- - Lot l{o. 7 , Highland Meadows Regional Slope Classification(s): Cp & D See Figure 4E Maximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Recommended Cut/Fill S'lopes: 2.5 H : I V Maximum Cut/Fill Slopes: 1.5 H : 1 V Regional Underdrain: Para'l lel to t'leadowbrook Drive on rear half of property. Anticipated Perimeter Foundation Drain Detail(s): Not applicable Compaction Requirement - t{on Structural Fi'll: See Appendix 8 Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches l'linimum Footing l.lidth: 18 inches Applicable for Basement: N0 Equivalent Fluid Lateral Pressure: 80 pcf Insufficient low risk area is available for safe develop'ment. Note: These recomrrcndations are a summary only for this specific lot. Refer to "General Recsnrnendations" for conplete details. -40- Lot No. 10, Highland I'leadows Regional Slope Cl"rrifi..tlon(s): A, B & Cp See Figure 4F Maximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : I V Maximum Cut/Fill Slopes: 1.5 H : 1 V Regiqnal Underdrain: Along south property line. Anticipated Perimeter Foundation Drain Detail(s): Figure 5A or 5D Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Append'ix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf l'linimum Footing Depth: 48 inches Minimum Footing l.Iidth: 18 inches Applicable for Basement: YES Equivalent Fluid Lateral Pressure: 80 pcf Structure should be located in class'A'or'8'areas. Basement should only be located in class'A'area. Grading should be limjted to class'A'and'B' are as . Note: These recommendations are a summary only for this specific lot. Refer to "General Reccrnmendations" for conplete detajls. -41- Lot No. 11, Highland Headows Regional Slope Clurrifi.ution(s):' A, B & Cp See Figure 4G l,taximum Cut Depth: 4 feet l4aximum Fi'll Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : 1 V Maximum Cut/Fill Slopes: 1.5 H : I V Reg iona'l Underdrain: Along south property l'ine. Anticipated Perimeter Foundation Drain Detail(s): Figure 5A Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fil'l: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf l4inimun Footing Depth: 48 inches Minimum Footing liidth: 18 inches Applicable for Basement: YES Equivalent Fluid Lateral Pressure: 80 pcf Restrict basement location to class 'A' areas. Note: These recommendations are a summary only for this specific lot. Refer to "General Recsnmendations" for conplete details. -42- Lot ilo. 12, Highland lileadows Regional Slope Classification(s):' A, B & Cp See Figure 4H ltlaximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : I V Maximum Cut/Fill Slopes: 1.5 H : 1 V Regional Underdrain: Not applicable. Anticipated Perimeter Foundation Drain Detail(s): Figure 5A Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 l4aximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing liidth: 18 inches Applicable for Basement: YES Equivalent Fluid Lateral Pressure: 80 pcf Note: These recommendations are a summary only for this specific lot. Refer to "General Recommendations" for conplete details. -43- Lot No. 16, Highland Meadows Regional Slope Cluriiri.ution(s): A See Figure 4I Maximum Cut Depth: 4 feet i{aximum Fi'll Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : 1 V Maximum Cut/Fill Slopes: 1.5 H : 1 V Reg ional Underdrain: Not appl icable. Anticipated Perimeter Foundation Drain Detail(s): Figure 5A Compaction Requirement - Non Structural Fi'l l: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Oepth: 48 inches l'linimum Footing }Jidth: 18 inches App'l icable for Sasement: YES Equivalent Fluid Lateral Pressure: 80 pcf Note: These recommendations are a summary only for this specific lot. Refer to "General Recommendations" for canplete detaiIs. -44- Lot No. 18, Highland l4eadows Regional Slope Clarrfficution(s):. A, B & Cp See Figure 4J l4aximum Cut Depth: 4 feet l'laximum Fil I Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : I V l4aximum Cut/Fil1 Slopes: 1.5 H: I V Regional Underdrain: Not appl icable. Anticipated Perimeter Foundation Drain Detail (s) : Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Appendix I Benching Detail: See Figure 6 I'laximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing l.ljdth: 18 inches Applicable for Basement: YES Equivalent Fluid Lateral Pressure: 80 pcf Locate structure in c'l ass 'A' areas. l{ote: These recommendations are a summary only for this specific 1ot. Refer to "General Recommendations" for ccrnplete details. -45- Lot No. 19. Hiqhland Meadows Regional Slope Clurrifi.ution(s): Cp, D & E See Figure 4K l.laximum Cut Depth: 4 feet l4aximum Fill Thickness: 4 feet Recommended Cut/Fill Slopes: 2.5 H : t V l.lax imum Cut/Fi I 'l Sl opes: 1. 5 H : I V Regional Underdrain: Not applicable. Anticipated Perimeter Foundation Drain Detail(s): Not applicable. Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 lllaximum Footing Bearing Pressure: 1500 psf l4inimum Footing Depth: 48 jnches Minimum Footing l.{idth: 18 inches Applicable for Basement: N0 Equivalent Fluid Lateral Pressure: 80 pcf Insufficient low-risk area is available for safe development- Note: These recommendations are a summary only for this specific lot. Refer to "General Recommendations" for conplete details. -46- o Lot No. 21, High'land tleadows Regionat Slope Classification(s):' Cp, D & E See Figure 4L l4aximum Cut Depth: 4 feet l.lax imum Fi I 'l Th ickness : 4 feet Recqnmended Cut/Fi'll Slopes: 2.5 H : 1 V Maximum Cut/Fill Slopes: 1.5 H : 1 V Regional Underdrain: Not applicable. Anticipated Perimeter Foundation Drain Detail(s): Not applicable. Compaction Requirement - Non Structural Fill: See Appendix I Compaction Requirement - Structural Fill: See Appendix B Benching Detai'l: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing tJidth: 18 inches Applicable for Easenent: N0 Equivalent Fluid Lateral Pressure: 80 pcf The regiona'l stability of this lot is affected by a progressive failure mode from downslope. Mditional studies are reccmmended to evaluate the possibiIity of reclassifying the class 'Cp'portion of the1ot or developing a scheme for protecting against a progressive failure. I'lithout these studies, development is considered high risk. ilote: These recommendations are a summary only for this specific lot. Refer to "General Reccrnmendations" for conplete detai'l s. -47 - Lot t{0. 23, Highland Meadows Regional Slope Clurrifi..tlon(s):' Cp, D & E See Figure 4M Maximum Cut Depth: 4 feet Maximum Fill Thickness: 4 feet Reccrnmended Cut/Fjll Slopes: 2.5 H : 1 V Maximum Cut/Fil1 Slopes: 1.5 H : L V Regional Underdrain: Not applicable. Anticipated Perimeter Foundation Drain Detail(s): Not applicable. Compaction Requirement - Non Structural Fill: See Appendix B Compact'ion Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 Maximum Footing Bearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing Width: 18 inches Applicable for Easement: N0 Equivalent Flujd Lateral Pressure: 80 pcf The regional stability of this lot is affected by a progressjve failure mode from downslope. Additional studies are reco{nmended to evaluate the possibility of reclassifying the class 'Cp' portion of the lot or developing a scheme for protecting against a progressive failure. |lithout these studies, development is considered high risk. Note: These reCommendations are a summary only for this specific lot. Refer to "General Recqnmendations" for conp'l ete details. -48- Lot No. 24, Highland Meadows Regional Slope Cl.rrifl.ution(s):' Cp, D & E See Figure 4N l4aximum Cut Depth: 4 feet l.lax imum Fi I I Th ickness: 4 feet Recommended Cut/FilI Slopes: 2.5 H : I V Maximum Cut/FiII Slopes: 1.5 H : 1 V Reg ional Underdrain: Not appl icable. Anticipated Perimeter Foundation Drain Detail(s): Not applicable. Compaction Requirement - Non Structural Fill: See Appendix B Compaction Requirement - Structural Fill: See Appendix B Benching Detail: See Figure 6 Maximum Footing Eearing Pressure: 1500 psf Minimum Footing Depth: 48 inches Minimum Footing }{idth: 18 inches App'l icable for Basement: N0 Equivalent Fluid Lateral Pressure: 80 pcf The regional stability of this'lot is affected by a progressive failure mode from downslope. Mditional studies are recommended to evaluate the possibility of reclassifying the class rCp' portion of the lot or developing a scheme for protecting against a progressive failure. I'lithout these studies, development is considered high risk. Note: These recommendations are a summary only for this specific lot. Refer 'to "Genera'l Reccrnmendations. for cqnplete details. -49- LIMITATIONS This report has been prepared for the exclusive use of providing prelimin- ary geotechnical design criteria for the specific lots included in this study. It has been based on widely spaced test borings, geologic interpretation and experience with other projects in the Vail area. It was performed in accordance with generally accepted sojl and foundation engineering practices. No other warranty, either expressed or implied is made. Because of the high degree of variability encountered in the subsurface conditions, conclusive recommendations could not be developed for certain areas. These areas are jdentjfied herein and supplemental studies are recommen- ded. Similarly, the analyses and recornmendatjons contained herein may not apply to lots that were not specifically investigated. Separate studies should be made for those lots to develop applicable geotechnical design crjteria. It cannot be over emphasized that safety, as it relates to natural slopes in particular, is a relative concept and that no slope is'safe' in absolute terms. The concept of rFactor of Safety' is used to express the relative safety under normal loading in the absence of active geologic processes (weath- ering, erosjon or landsliding). However, in time, these geologic processes wiI l result in the failure of any natural slope, regardless of the factor of safety. In general , the time required for this to occur may be very great for the entire region, but a specific event may occur at any time. Since the conclusions and recommendations contained herein constitute 'preliminary geotechnical design criteria', Fox & Associates should be afforded the opportunity of reviewing the project plans and specifications and observe the construction to determine if our recommendations have been properly imple- mented. 0nce we confirm that they have, the recommendations may be considered final . If we are not afforded this opportunity, these recommendations shall be -61- considered only as 'preliminary' and no given. FOX & ASSOCIATES OF COLORADO, INC. Ronald F. Holcombe, P.E. Project Geotechnical Engineer RFH/cp assurances as to their suitability are Reviewed by: Donald R. Clark, P.E. Principal Geotechnical Engineer Q^*l? /LfuL $),$tii:Ta?&-6' 21078 3 -62- 1. Peck, Ralph 8.,"Stability Mechan ics BIBLIOGRAPHY of Natural Slopes", Journal of the Soil and Found at i ons D i v ii iiilTSFeT6-Tiliie- 93 No.5M4, r]uly 1967 ?. DrAppolonia, E., Alperstein, R., and D'Appolonia, D.J., "Behavior of a Colluvial Slope", Journal of the Soil Mechanics and Foundations Division rvo/ 3. Zaruba, Q., and Mencl, V., Landslides and Their Control, Czechoslovak Academy of Sciences, 1969 4. Pal ladirro, D.J., and Peck, R.B., nSlope Failures in an Overconsolidated Clay, Seattle, l.lashington", .9@., No. 4 Tan, Ll.H., Yuceman, M.S., and Ang, A.H-S, Design of Soil Slopes", 201 (1e76) "Probabil ity-based Short Tern Canadjan Geotechnical Journal 13, 5. 7. 6. Tweto, 0gden and Lovering, Thomas S., Geology of the Minturn 15 - Minute Quadrangle, Eagle an s- ' 1977 ' and Rogers, tJil liam P., Earthquake Potential in Colorado q pleliminary evaluation l Kjrkham, Robert M. urvey, In addition, Bill Andrews of the Town of Vail, Bob Lloyd of and David Peel , Arch'itect were of great assistance in providing information, as-bui1t plans and background data. The authors would like to acknowledge and thank the following 'in our firm who made major contributions to this study: Michael Brown, Engineering Geology Alice Campbell, Support Services Cindy Carlson, Il lustrations Ray Costin, Laboratory Manager Lori Finn, Laboratory Testing David Glater, Engineering Geology Steve Gray, Field Exploration Jim Grippa, Field Exploration Carrie Pospisil, Typing l'lalter Schultz, Coordination Robert Sennett, Technical Review KKBNA, Inc. topographi c individuals -63- I : I I I A /. 1 ,/' /tl ,,,I I I i I I I i ,l ',t ''l 'l =.,.- \ \3,1 \e'rl Y rl I Hliiitiiiilihl: !i.J ol [,"ffi. 1,', *'' 7 ->. -1 T \, r, \\ \6\\\t \tr \Y' )' ^4,/-1 ri\\ .{ \ r\.'.\\ ! \ \V/ \\ \ \ \.' \u ,\ \q !i T\ iA\ \.r\t I \i.-\,o \o l- 1 !,F r s)i-l I R F r{ Ll !. =t tl- u o :iiii,- : i:; l''. ftitii t :a c {=it ,!r i 2l i'a Hl :!ft a.!!c ot cro art gr. "iN)iNlZ'' i t'i 'i;ii.\t_t ._ * l,i it-" o o + ?tN r'.. \ o\ -1'-' x* Y '\{r\.\ . \i'11\\7i f /,.,e | .',,i, \l\l;s /.' \ .1.. 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'. t)'. \ o (rt o 5S\r\, I o o c IT t o F F b|o *E z rJ (, tt o e,a T 1ll (J o< HH of ulo =ql ;;tr -'f LJ *< =lL rl;o9 ,z 59 o< ull (Jl fit Er p o al o g c \ LI E 3 r.l !. t;r jx rl t iE Oq LI & .l LO ,.8 x< BI tro lrl <FIL ZE Btf O(, o g. tr o !,1 E Fl lr. t&;oF E;9-r ga € FI gr rO I FI o FI Fl I FI t 3 8 c)€ 6a FI o F. (ii 6 gr| g oo JT Irl tr 3 I g. BI I o -l o -l z o F F o E ra .g 00 -9 o a,(,.o c € 9| q, a, .E oo c EI oo E =r^c o tJ )<o F z sl EI F o E g. tr o |l. lrJ o lr.E I o pl tr D rf IL EI z q o trl E (9 o tr r tr o g. EI (J h E D Q I rrt =tl {3 !-a Fl lr. E; tol H\ el pl o 6 tr TE <i , Ql \ H; \ oEl I zE . \ p(,\\ tt \p € !-l or |a I r{o i Fa a FI d z € Q 6a € €{ FI o FI o G E N a, oo tu o z gl 3 o a o gJ E 3 rt tr. lrl o q e E (,o E I tl tl ll"' il.s ll 90 lo tro IE ilat IE Ia l$[tr too I tll loo t.E i3 ira IE 6 F sl 13.o IL o tr o f;2. g. o lrl F p !r.o a CURVE B to'l PROBABILITY OF to'2 ro'3 FATLURE (LOG SCALE) JobNe 1-1101-5916 IDEALIZED PROBABLISTIC DTSTRIBUTION Date lO/13/83 Comulting Engineers and Geologists ll IECEND A' bs rlrl rrca l' llodcrrte rlrk rrca C.r.Htgh rlrt rrca' Progtcellvc Frllurc q'ntrl rlr} lrce'Flret Eveni D' VerY hlgh rlrh rrcr E- Unttrble -- Hczard Area BoundarY SCALE: 1'= 50' HIGHLAND }IEADOWS SUBDIVISIOT\i FTLING NO. T LOT NO. I vAlL, coLoRADO ' B i JobNo: 1'1101-5916 SLOPE HAZARD MAP Dare, 9/27 /83 Contulting [ngineers rnd Geologists l{ IEGEND A' low rlol rrec B' Hodcrrtc rlel lrca Cr.Hlgh rlrk rrca' Progrcrllvc Frllure Cr-Htgh rllh arca'Flrct Event D- Vcry blgh rlrl rrca E Unotrble Hczcrd Area Boundlry SCALE: 1'=50' HIGHLAND MEADOWS SUBDIVISION FILING NO. I LOT NO.2 VAIL. COLORADO Job No: l.l101'59f 6 SLOPE HAZARD MAP Date: Figure 9/27 /83 o o 3 , tfl \E lo /s=o I o E dti LOT IIAEND A' los tlrk rtca B' ll-odcrrtc rlrk rrea G7-Hlgh rlrl rrca' Progrcrolvc Frllure C5'Hl3h rlel rrce'Flrei Event D' Vcry hlgh rlsh rrcr E Unrtrblc Hazord Area BoundcrY SCALE: 1'= 50' HIGHLAND MEADOWS FILING NO. 1 LOT NO.3 VAIL. COLOBADO suBDivlsloN r SLOPE HAZARD MAP l-J"b N", , 1-1101-5916 Dare, 9/27 /83 Figure 4C o o r{ I t s o s o a s{us J.EGEND A - Lour rleh area B - Moderate rlck area Cp- Hlgh rlsk area- Progreeelve Fallure Cp- Hlgh rlsk area- Flrst Event D . Very hlgh rlek area E - Unstable --- Hezcrd Area Boundary SCALE: l'-50' HIGHLAND MEADOWS SUBDIVISION FILING NO. I LOT NO.4 VAIL. COLORADO Revlsed; l/g/84 SLOPE HAZARD MAP Job l,fo: l-110f -5916 Conrulting Engineers and Geologists Dare, 9/27 /83 il D LOT .-____ ESEND A' bw tlrl rrea B' Dlodcrrtc rleh lrcl Cr. Htgh rlrl rrca' Progrcrelvc Frllurc CFHlgh rlek lrca'Flrtt Event D' VerY hlgh rlek rrca E Unettble Hazard Area BoundarY SCALE: l'-50' HIGHLAND }IEADOWS SUBDIVISION FILING NO. I LOT NO.7 VAIL, COLORADO I Job l,lo:1-1101-5916 Date:9/27 /83 SLOPE HAZARD MAP Comulling Engineers and Geologisls LOT TO T.EGEIIID A' bs drlarea E ll6dcrtte rlsk area C,r- Hlgh rlrl rrcl ' Progrerelve Fallute G9-Hlgh rlek rtca' Flrst Event D' Vcry hlgh rlrl atea E- Unrtrblc Hazard Atea BoundarY SCALE: l'=50' HIGHLAND }IEADOWS SUBDTVISION FILING NO. I LOT NO.10 VAIL, COLOBADO SLOPE HAZARD MAP Job l,lo: 1'1101.5916 Conrulting Ingineers rnd Geologisls Dare: 9/27 /83 tigure 4F t{ IEGEID A- lPs drl rrcc B- Dfodcretc rlrlr rrea Gp.Hlgh rlrt rrcr' Progrcdvc Frllurc CFHlgh rllk rrca'Flrst Evcnt D' VcrY hlgh tlsl rrca E- Unttrblc Hazard Area BoundarY SCALE: 1'=50' }IIGHLAND MEADOWS FILING NO. T LOT NO.11 VAIL. COLORADO suBDiVlstoN I Job l,lo, f 'f 101-59 I 6 SLOPE HAZARD MAP ( \/'l LEGEND A -Low rlck area B -IUoderate rlrl area C9- Hlgh rlsk area'Progrecelve Fallure Cp Hlgh rleh area'Flrct Event D 'Very hlgh rlsk area E . Urmble --- Hlztrd area Boundary SCALE: l"= 50' HIGHLATTTD MEADOWS SUBDIVISIO N FILING NO. 1 LOT NO. 12 VAIL, COLORADO Jobl,lo: 1-1101-5916 SLOPE HAZARD MAP Date: 9/27 /83 Comulting fngineere and Geologisls r{ A IICEND A- lor tlch rtca B' llodcrete rlsk rrcc Gr.Hlgh rlrl rrce' Progrcrlvc Frllure GFHlgh rlrk rrea'Flrst Event D' VcrY hlgh rlrlr rrca E Untrrblc Hazard Area BoundarY SCALE: l'=50' HIGHLAND }IEADOWS SUBDIVISION FILING NO. I LOT NO.16 VAIL, COLORADO ' Job l,lo: 1-l 10 1-591 6 SLOPE HAZARD MAP Date, 9/27 /83 Conculting Engineers and Geologisls il / LEGEND A 'Low rlcl crea B 'Irloderaie rlck area C7 - lfthrth rrea' Progrceelve Fallurc Cr- Hlgh rletr area 'Flret Event D - Vcry hlgh tlsk crea E . Unctable Hazard Area BoundarY SCALE: 1'= 5O' HIGHLAND MEADOWS FILING NO. 1 LOT NO. 18 VAIL, COLORADO suBDrvlsloN I Job No:1-r r0r-5916 SLOPE HAZARD MAP Dare, 9/27 /83 Comuhing [ngineers and Geologisls \ LOT 19 io ,J q &e o s 6f- |sol |EAEND A'Low rlsh area B' M-odcrate'rlek area Cp'nlgh rlal area'Ptogrcedvc Fe Cr' Hlgh rlsk area- Flrct Event D'VcrY hlgh rlsk area E'Unsiable Hazard Area BoundarY llure SCALE: 1'=50' HIGHLAND TTIEADOWS FILTNG NO. 1 LOT NO. 19 VAIL. COLORADO suBDiVtstoN SCALE: fU tio, l'1101'59f 6 SLOPE HAZARD MAP Dare: 9/27 /83 Conrulting Engineers and Geologisls D LEGEND A'Low rlsk area B' Mcderate rlgk area C9' Hlgh rlsk crea' Progreeslve Fallure Cr' Hlgh rlsk area' Flrst Event D- Very hlgh rlsk area E. Unctable --- Hazcrd Arca Boundary SCALE: 1'-50' HTGHLAND MEADOWS FILING NO. I LOT NO.21 VAIL, COLORADO suBDlvI{;loN I SLOPE HAZARD MAP Job No: f '11O1-5916 Dare: 9/27 /83 4L Figure l{ IESEND A' Los rlllr rrca E lNodcrate rloh lrea C4.Hlgh rlrl rrca' Progrclrtvc Frllure Ci-fffgt rlrh rrea'Flrct Event D' VcrY hlgh rlll lrca E Unrtlble Hazard Area BoundarY D// cP /'^us'o> "*.).-/ ,/ SCALE: t'=50' HIGHLAND }IEADOWS SUBDTVISION FTLING NO. I LOT NO.23 VAIL, COLORADO I Jo,bNo' 1'1101-59f6 SLOPE HAZABD MAP Dare, 9/27 /83 Comulting [ngineers and Geologists I \ * E ESEID A' lou del rrca B' Hodcltte tlel rrca C..r.Htgh rlrl rrcr Progrcrlvc Frllurc G3-Hlgh rlrlr rrcc'Fltet Evcnt D' Vcry hlgh rlol lrca E- Unrtrble --- Hazrrd Area BoundarY SCALE: 1'= 5O' HIGHLAND MEADOWS SUBDIVISTON FTLING NO. I LOT NO.24 VAIL, COLORADO I JobN.t, 1'110f'59f6 SLOPE HAZARD MAP Dale: 9/27 /83 Comulting Engineers and Geologisls c o tt t o E o o \\\ \ ,- Foundrtlon gtlt \ l \ Eulldlng p.par oeGr op.n lolnla rnd on top ol grrvcl Dllnlnua 8 Inchcr ol cltrn grrvel (nlnlnun O.75 Inch rkc) Polyethylcnc E Inch dlractcr drrln tlt... .prc.d t/rl lnch lprri OR p.rtor.t.d Dlpc. Dbchrrge by grrvlty or D.chrnlc.l Darn3 io r .ultlblc outt.ll. Vlnyt pl.3tlc plpc lr rcccptablc' DETAILS OF DRAIN SYSTEM NOT TO SCALE Feure 5A f ! O E f Bulldlng pap€r ov.t opcn blnr and on top ot gt vcl. Mlnlmum E Incher of clcrn grrvcl (rnlnlnun 0.75 tnch rlzeL Mlnlmum { lncher of clean gravel (mlnlmun O.75 Inch rlzc) Conncct gravcl under rl,rb to pcrlphcral draln it one ot mor€ Polnle Polyerhylcnc t loch dLrrtreter dnln tltee. rpaced l/f Inch apara or pcrforrted plp€. D|.chlrgt by gnvlty or ncchanlcal ocanr to r sqltrble porldvc ourfall. Vlnyl plastlc plp€ l. .cccpr.blc. DETATLS OF DRAIN SYSTEM NOT TO SCALE Frgre 5B o c !t ,0 E s 1t Fo[ndltlon rrrll illnlouu 6 Inchcr ol clcan gravcl (nlnlnun 0.75 Inch rlzcl under rhb, rlope to tltc, olnlnuD l/t Inch gcs tooi. CoDprct d plt run !r.e.l Mln. 2it' g lnch dlamctcr Pcrforalcd PlPc OR drlln tllcr {rplced l/tl Inch rPert' covcr lolntr) Slopc plpc DlolDrm l/t Inch PGr foot to .ultrbL outlct. NOT TO SCALE DETATLS OF DRAIN SYSTEM Consulting Engineers and Geologists o c E l Ftoor lolrtr Gradc beam ry - Crawl .p.c€ A,, Polycthytcnc glucd to sall rnd artandad along bottotD of arcrv.tlon Mlnloun l0 lncbcr ol rruhed gnvcl (nlnlnuo 0.75 Inch rlzcJ I lnch dlrn.t.r pcrtor.tcd plpc OR opcn.lolntcd draln tller bprccd l/f lnch rpa6, cov.r lolntt). Slopc nlnftnun l/t Inch gcr loot to porltlv. gravl0 outhll. Vlnyl pl$tlc plpc L .cccptlblc. NOT TO SCALE DETAILS OF DRAIN SYSTEH Consulling Engineers and Geologisls c o ?J 0 E I| o +Crawl rpacc ;>L__>1 Polycthyhoc oolrturc barrler 3 hch dlrmeter drrln dle. (rpaced l/4 Inch .p.rL ln clcu gnvct (nolnlmum O.75 Inch r|'cl Pcrforrtcd PVC plp OR Slopc mlnlmum l/E Inch pcr toot io . aunp locrtcd In crawl rptcc. DETAILS OF DRAIN SYSTEM NOT TO SCALE Fryure 5E o o E t E = rl e6 3EP r$E 0.r Dtitr is€iEE /'=la ,' !;E / 3E-t $Ht O A o o E 0 E I c rt I E lrl .g o 6 o A o l.I \// / //^l ti €o BE YO B(a rE {' o ( I I I I I I I I G |, ID o G t:o N o i5 r{ rO c o E o o I o 0 o A o l5 6 a €z \0 F.o\lo a FT o t{ F{I F{ o z &o EA o t)N o -t-a a, .!o E @ \9 o sl A o -J o -J &D F z d F 3rl o I z o z lrl EI li I rA li btt O, li 0rf trti oo:tr1,r! ll oo'Eir vt i.tr:'o:uii il ti 3l u ta oo o o a,(9 l! ilI f;,it 'i !r!!E :;i!i;! ::igr:: ii.- iiiiliiii ;.i iril fil l.i r gt t- \ t'... \ ,r'l tr t1\ \' "\ii\ \' .'.-:\ t_.\ 1(o :,.i.'.rp.<(\..\o \\,''. \ r\\.r i\' 1r:.5 ,li '"' P'-"",tl''','i1i\$\1\-.r' V' /"- q', / ./\ /t/,n ,/ )'z'\'- ,t/ ,\<'.r''\i\\\)$\$.\.')'l-\)X'. .l:\\\iNif/.';," ,,-_^ _ i , '\r\{y{\''\',,,,'.r.Ni\1iN .,.,,: -/ ri\i' ,,"r1)\x':, .,. "\i\N\:r.V', ;/;/" a,,l "... "\i1.r\i'\:.Jl /,/,---,',. _"), t'..tir\]rt1)\..\\i,\Z'' it;'-:til -\$;\\ \ \"\\\\ i'v/-' /;/..-6.l-_-..,.\i,a.1.. r.t.\r,r\'...-'i::." ' ,t.i 1'; -.(\A't'.. '\"' /'l' \-i'N X \o \-_ - I I I a\\€\ |l\,, 2"1 '. ao 6 z z -J z nJ E ( n) o t t O g{ APPENDIX A TEST HOLE AND LABORATORY TEST RESULTS : O E-=E U a, 6 Or, Far>!c !E a, o - =E t e" EE"E r, >! oo o6.s (t e ltl 5 -b - *o '.9=.;oP-I -c ' rl, O O5 u tE '^ .Po c.t6p c € tarEo t! tU u E e- O € o rl, ort PE t F Ctt dOnE d .orJ ir c ,50,e 4,,E <rF .c FL. e'o .rr oo!, E e ,N >r ?.O (1, --rFF !'! . P E X.C E -6{E |!!r |! C @ 6> t O O.c-<h oF o ltt-3 6te{ dE c a, F.P !. o !, 'FcE o>rl,c 'o.r d |-.- o L o >r C E qre.C e C 6 F .FE g 5 O ,< rl' (,, rUa,O,O o !o> eo-o.- 3 l^f o. >r au eoo o. Fo! E66'-9 J F O' d O.C A' .r '! t L 6 o !- F.- .tEoE l-c{,rd-c>.c O!, E E .|,.Pde .J P! , -. E .r'F Ot-.J (U x.C.- rl, o e rU o . l! ' .t o o 'oE - t (!|. r c rdrl, o Ln rl, {J. a, a-64, E,ur6 d OL L .- >Ee € 5 s ru r! . nt c, or c! rl,io o.c eo orF !r- i!, a,r 3 Ld 6 !Ua,<- Tt, LEr rlrJ rl,ag| ! o i 3 .16 ()f ,- 6O lrF lrt o, or h a, o o.J \o 3* E- .:" F.:9'-bEg -6 Pc --a,u 'ce -= .- bE) g.:Ebg o4t -o c od .ee >!o Eo6r!e r.- Ji a.o-t GC O O q' .t il'{rc o.to.-L .P- coo !r-.J o-! Frs a o '!E -? --t @ ood ar. (JE. eh !o.(J ><Ft- o€o '!s oo'u rl) od o)o0, -.t0, l-d 9ro - x i.t -c .r ! o 6 ! o 6, r-a,, aE9 o+' F ! !(U!-Cc!+rE (6Ct CC, qrp !.r oa, qJ€r e.!c/ar.F a o E- E- rlJ 4rd-ce d (rl FE va\o F! FoV lo!<)s 6t.zle N .a .|{E9 EJ L(J va, ,!to POE o!o o it4 c o E€ L'E 3 ;E ,^ o ll,< FL,o at th 6 oa o U L(-'a cDv \F O. rr-E tC 'O art LQ('l .a .6 C x>!5 orlr.Eo-t. >!.l tA t,vr uo or !?e>r E ol- o F o o<F-.E:4 Vrle o, I {J rl,>!o tu >rL F E o .r ., !,>lor r, ', o FI Jlr-, E ;* ;l =.J .- aa oar6 Jl 6e .J 6lE il ". '. aE i 3 rrt >. e |^lL I |.o - Ll o urt ar.r , lat a, .,Jl ol >- 6 I-5l gl ..s .dlt 3 3 el il =lg il il' € € e1 Pl fl dl: dl 513 : s EIEE S Em {r', \ { N \{ *\ $ 5 { ***fu su 5\s Nq No* N \ N RN N N t) e $\ \N \ \ \ li \ \ \ \ \ $ \ \ \ \ \ \ s \ $ & t"tt fi-'to o ta 0 t * Pro!:ct Highland lleadors at Vail Ptorcct No. l-l l0l-5916 Borlng No. -- l{ll- 4 Tot.l Deprh 69.4 ProJect Manager Ron Holcombe Fleld Engr.,zGeol. Mike A' Brown Drlll Rls --- -1.5!-- , Steve Gray Drlller Surllce Elevr tlon Depth Log Sample Locatlon x Rec. RQD Llthology Notes 0 - - : - : f- a I I I T I r r l0 20 30 35 40 45 50 Dri 1 led wi th 4" sol id auger 6/6 1/6 ST 300 psi CB 7/6 7/6 lio sarnple taken set surface casing ]to depth 20 feet. I Drilled Hith 3-718 inch dia eter rock bit sPT l4l5 l3/6 ?o/ 6 Artesian water at depth 25,0 feet. Flo{ing at approximdtely I gPn at su r face cB 30/r0 sPT 18/6 3t/6 3Ot6 Hole caving at depth 36 feet. Artesian flow increased to approtimately l0 gpn. Cannot advance hole rlith conven tion.l rotary drilling method sPT 2016 30.5 off-set hole l0 feet southtest Redrlll with hollon stem augers, sPT 50/5 - - SPT 50/6 ffi IIAI{-MDE Fltt, tenporiry placement for CLAY, very sandy, silty, scattered gravels, sA 0, clayey lenses, stiff very stiff, moist, brovJn (CL-SC) Sedlmentary rock fragnents CB 5r CB 5PT GRAVEL I SAIID in CLAY matrir, rtrd||J large boulders, cobbles, sA 0 (SP) seams, medium dense to dense, ret, brown (6C-SC) Sedircntary and lletamorphic rock fragments SIIALE E 5AI{DSTo E, very dltered, wea- thered, probabl:/ di splaced: Claystone, Si I tstone. micaceous. this distorted beddingi i ntern i tant discontinuous sandstone lenses, Bedd ing interrupted by faulting or mass failure, nediudr hard to hard, noist, green to brorn (ct-il1) CB 5PT HtrJq SPT spT SPT SAMPLE SYMBOLS C8- Callfornla Blrrcl (btowt/hc SPT' Standard Penetrlllon Test (blou./lnch) ST- Thln Walled Shelby Tube NX' Core, dlam€ter 2.155 Inches LOG OF EXPLORATION HOLE Consulting Ingineerr and Geologists Dot"' 9/lqlg: Flgure: Al-2 ProrGct tliqhland l,leadows at Vni I Prorcct No, Borlng No. r - ll0l -5916 Hlt4 (contlnued) Totrt Drprh 69.4 Surfacc Elcvatlon Prorect Manlgct Ron Hol combe Fleld Engr./Gcol. l'.|i ke A grorn Drlll Rlg ---Ll!Drlller Steve Gray Depth Log Sanple .t Rec. RQD Lllhology Note j - - : : : : t - I I I I r - t 50 ti 60 65 sPT t8/6 36/6 sPl 23/6 27 /5 sPT 50/4 - SMLE t SAI|oSTOIE continued SPI SPT SPT Total oeoth 69.4 feet SAMPLE SYMBOLS CB. Callfornla Earrel SPT'Standard Pcnctrrtlon T€Et (blowr/lncht ST. Thln Wallcd Shelby Tube NX'Core, dlrmetcr 2.155 inches LOG OF EXPLORATION HOLE D!te: 9/14/83 Flgure: Al_3 ProJ.ct H lqhl and rb.do{s at Yall Prol.ct No. Eorlng No. r-Il0l-59r6 Torrl D.prh 53.6 Surfacc El.u.tlon Prorsct Muaget Ron Holcombe Flcld Engr .,/Gcol. l.li te A' Erodn Hfi. 19 Drlll Rlg 455 Drlllcr Steve Gray Dcpth Log Samplc * Rrc. RQD Llihology Notet . - l F r I t I r 0 5 l0 l5 20 25 30 JJ 40 45 50 cB t3/12 aau psl 300 psi 'to/6'i.216 t5/6 9/6 spr 'f 6/6 24/6 16/5 sPT l4/6 9t6 t't/6 Auger refusd l nt begain core r un. depth 43.0 feet ;qI s ToDsoi I CLAY, very sandy, silty, fer gravels, s ti ff, noist, brown (Ct) CE CLAY, silty SILT, clayey, interbedded, grades to SAtlo, clayey below depth 15.0 feet, stiff to very stiff, moist, brovrn (Ct-ilt-SC) ST ST CB GRAVEI- & SND in CLAY matrix, large boulders, cobbl es, nedium dense;'mlst to wet, brolrn ( GC-SC ) Rock fragnents of sedimentary, I gn eous ind metarbrphic origln. CB 5PT SPT SAI{oST0{E. rEdi un to co.rse gral ned, xell cemnted, delonltlc cement, massive, ipderit€ly f ractured, sllghtly orldlzed, hard, nblst, light qray to brom (sP) t{x 90 aa >IALL, )r ltstone tno llaystone r,l ln ln- terbedded srndstone'lenses. mlcaceous, thinly bedded, s llghtly carbonaceous,very fractured alonq beddlnq Dlanes (+lalo dlD). metrl si'lfldes.-hard. rbist d.rk sray (il1-CL) SAMPLE SYMBOLS C8. Catlfo/nh Errrel (btowr/lnch.r) ST' Tbln Wrllcd Shelby Tubc SPT- Stlndird Pcnstr.tlon Tcst OloI,./ Incbcrl NX- Core, dlametcr 2.155 lnchss LOG OF EXPLORATION HOLE Drte: gl t4/53 Flgure: Al -4 Prolcct Slahland tle.doris at vail ProlcctNo, l-ll0l-5916 Borlng No.Hr-.|9 (contlnued) Tottl D.prh 53'6 Surfacc El.v!tlon Prorect Manrgsr Ron Ho lcombe Fleld Engr./Geol. lill le A- Srorn Drllt Rlg 45s Drlller Stev€ Grav Dcpth Log Samplc r Rec. RQD Llthology Notcr 50 X 94 21 SHAL€ contlnued Iotal 0eDth 53.6 feet SAMPLE SYMBOLS CB- Callf ornla Barrel ST- Thln Wllled Shelby Tube SPT. Sr!ndard Penetratlon T€st NX- Core, dlamcter 2.155 Inches LOG OF EXPLORATION HOLE Date: 9/t4/83 Flgure: Al-5 ProJGGt Hi oh land ibadows it Vail Pror€ct Managcr Fleld Engr.,/Geol. Ron Ho lcombe Prorcct No. Borlng No. Tor.l Deprh 't-ll0l-5916 l'li ke A. Erown Hll-21 DrlU Rlg 455 59.0 Drlller Steva Gray Surface Elcvrtlon l0 l5 ?0 30 Jf, 40 45 50 ST 450 psi cB 4/6 4/6 ST 200 psi sgt 3/6 316 6/5 cB 4/6 316 sPr 4l /6 l9/6 CLAY, very sandy, sllty, interbedded sA 0, clayey sedms, few gravels, stiff to very stiff. noist, brolrn (CL-SC) Scattered sedlnentary rock fragrrents GRAVEL E SAxo in CLAY matrix, m;ny large boulders, cobbles, SILT seans, mdium dense, molst, broun (GC-sC-Sll) Rock fragmnts of sedimentary lgn-"ous and netafbrphic orig in. e SILTSToNE. vell cemented, doloni tlc ceflpnt, thinly bedded,.mas- !iv€, noderately tr SAMPLE SYMBOLS CB. Calltornh Blrr€l Gloint/hch.d SPT' Standard Pcnetrlllon Tesl (blos/ ST- Thln Wrll.d Shelby Tube NX' Core, dlamctcr 2.155 Inches LOG OF EXPLORATION HOLE Date: 9/14/83 Consulting Engineers and Geologisls Flgure r Al -6 Pror"ct Hlahland lleadod< 'r vall Prolcct No. Borlng No. l-t l0l - 5916 Hlt'21 (continued) Toral Dcprh ---!L0 Surface Elcvttlon ProJcct Managet Ron Holconbe Flcld Engr./Geol. llike A. Erown Drlll Rlg 4ss Drlller Steve Gray Dcpth Log Sample , Rec RQD Llthology Not€s 50 55 50 t{x 't00 90 SAI{0ST0I{E I SILTS]fiE continued Total oeDth 59.0 feet CB. Calllornla Barrel ST. Thln Walled Shelby SAMPLE SYMBOLS Tube 5PT. Standard Penetratlon Test NX- Core, dhm€tcr 2.155 tnches LOG OF EXPLORATION HOLE Date; 9/14/83 Flgure: Al-7 Prorect Hlghland readoirs at Vail ProJect Manager Ron 8ol corbe Fleld Engt .,/ggsl. ike A. Brown 455 Prorccr No. l-llot-5916 Eorlng No. Hll-24 DrUl Blg Total Dcpth 76.5 Drlller Steve Grav Surtace Elev!rlon ----!4 Depih Log Sample * Rec, RQD Llthology Note s 0 '10 l5 20 30 40 45 50 t9l6 t4/ 6 t6/6 to/6 4/6 7/6 ST psi ST 300 pst 7 /6 2t /6 6/6 c8 9tl sPT l516 21/ 6 29/4 Auger refusal at depth 43.5 feet. Necessary to rotary 215/16 in di. meter tricone bi t. bpso i '/l 'Nti J5; H '}ii CLAY I very sandy, very si I ty . str f mni <t - (al -qcl GRAVEL & SAIID in CLAY matrix, n€dium dense to dense, n€diur moist, brown (sc-Gc) Sedin|entary rock fra$|ents 5Pt CLAY, very sandy, silty, interbedded SAI0, clayey t gravel clayey lenses,stiff to very stiff, mist, brorn (CL) (Sc-Gc lenses) Scattered sedi rcntary rock fragrEnts SPT 5T 5T c8 GRAVEL & SAIID In CLAY matrlx, many 'large boulders, cobbl€s, mdiun dense to dense, moist, brom (SC-GC) s9T SAMPLE SYMAOLS :__ CB. Callfornla Brrrel (blogr/lnch.t) ST- Thln Walled Shelby Tube SPT- Standard Pcn€tratlon Tcat NX- Core, dlameter 2.155 Inches (blor.r./hch.., LOG OF EXPLORATION HOLE Consulting Engineers and Geologists Drtet 9/ t4/83 Flgure: al -8 Prolect Nlohland eddo{s at V.l I Protcct No. Eorlng No. t - |l0r -5916 Hil-24 (continued) Totrl D"pth 76-E Surflc€ Elevlilon ----!4 ProJect Manager --!9q.!9l99nb!Fleld Engr./Geol. --!i!CL,.-9.I99 Drllt Rlg 455 Drlllc, Steve Gray Dcpth Log Sample * Rcc RQD Llthology Notes 50 -60 -65 -75 _du - - |- F - T - I Begin core at depth 67.7 feet ffi GRAVEL E SAI{D continued )AnU5|UNLr llne tO rEolum gralneo' nl- caceous, |t|assive, slightly fractured, dolomitic celEnt, very hard, moist, light gray t{x 95 20 SHALE, Claystone t siltstone, possibly d i spl aced, very fractured, sandstone fragEnts, poor to Hell indurated, hard, moi st, darl gray Total D€Dth 76.5 feet SAMPLE SYMBOLS CB- Callfornh Barrel ST. Thln Walled Shelby Tubr SPT- Standard Penetr.tlon Test NX. Core, dlrmet€r 2.155 Inches LOG OF EXPLORATION HOLE Drtc: 9l14/83 Flgure: 11-9 ,a .l a t E o o ro 0r rr' I ar) @ Or O'l q, G'A o I r-l o o o F 3r ot O' 69 o I 0 z ,o o i ici 5i !u E. 'O ci "Ei I (,z F o EI,F tr o F E o t0 J ll o E E E p tt i.9F: c)co <t a E -l o o D 0 A ro r.o g) N lJ) O\OrFFrO (\t (') Or (v)(Y) AI (\I slrOsfh(\JCD st (\t N (\l 6l (\l ErEs GI <I O=-t o gr o @ro oo l') Lf! r..t F OOr- F.F-'. Eis' @OOr\st <t r- r- or) u-t -.F-FF. @F-N1\ Or@O(nO \l c') Lt @ro At (Y) ro st r- Or (\l CO (\l r- r n- 3-l E<E(U 9!6F =tt .t, s U' E= ;3 oooooorfroooooorooooo I O . OO or G) or <t o-. or st o -f ol lr) o tJ) sl . . cn -t ot =f o g)(\t C\l ('rF st r- (v F At Olp r (\l !ij ) UI ,I a v, t )t IU (l, = ! -J .C ? PARTICLE SIZE ANALYSIS CHART :p - o tt A z |ll trl Desorhdon clayey SAND & GRAVEL Locatioll Test Hole HM-]0 Depth 4.0 feet % C'rad 2l It Sand 45 5 Sft&Oay 34 Atterberg lLnfts LL Pl Cbsificadbn t.hified SC-SI4 /MSlfTO Descrbdm SAND Lqthn Test Hole Hl{-ll Depth .|0.5 feet 90 t0 z o o A z t&l L) E lrl c t0 to % Grard 33 % Sand 55 5 Sft & Clay 12 Attaberg Lnits LL Chsdncadqt: Unfred AASITTO c) m PI sr.r 0 100 90 Oescrbtcr clayey GRAVEL t@tin Test Hole HM-.|6 Depth 9.0 feet I z tt a A F =trl o E Il I 70 60 50 {() 30 20 5 Gravel 53 x Sard 26 5 Srlt & Clay Atubery[nlts Cbcsmcadorr 21 LL lHid AASHTO PT GC-GM 762 38.1 19.1 DIAMETER 95'2 4:15 23t l.r9 5n 2yt .r{9 .O7a OF PARTICLES IN MILLIMETERS PARTICLE SIZE ANALYSIS CHABT Job No: l-ll0l-59.|6 Date: 9/9/83 Figure A1= 11 SLR.I PARTICLE SIZE ANALYSTS CHART OeqhOorr clayey SAND : e 2 q q A F z (J trJ A Test Hole HM-.|9 Depth 20.0 feet bJ E Silt & Cfay Attcrberg enfts Cbssificatirrr Unified SC-S14 AASIITO z o o z lrl (', E l,rJ A Oesctptm claYeY SAND Locadon Test Hole Hll-.l9 Depth 25.0 feet SCrrald 9 t Sard 67 E Silt& Oav 24 AutergEnits tL Pl &sdficatin: tjnffi€d SC-SN AASHTO Desabdar ciayey SAND & GRAVEL I z tt o A F z c|o E trl I Test Hol e Hl'l-2] Depth 29.0 feet E Gravel 28 A Sard 48 5 Silt & Oay 34 Atdergenib lI Pl rb..rf,."fi.!G lJtfih SC-SM AASIITO DIAMETER 95.2 4.76 2J8 l.l9 5tn .gn .t49 .O71 OF PARTICLES IN MILLIiIETERS PARTICLE SIZE ANALYSIS CHART Job No.: 1-ll0l-5916 Date: 9/9/83 F6ure Al-12 SLR.I PARTICLE SIZE ANALYSIS CHART : z c,o z E A OeecrbOqr SAND -& GRAVEL L@arixr Test Hole Hl4-23 Depth 4.0 feet % Grawl 59 E Sard 28 tt Silt & Oay l3 l0 0 (n Attefterg Enic LL Chsiftcatirn: Unifred GP AAS}ITO I (9 z o tt, A z I trJ A D&ipdan claYey SAND tocarin Test Hole HM-23 Depth 19.0 feet %Gnret 13 % Sand 60 5 Slt& Oay 27 Atnabers hnits LL Pl Chsdficalin: lJnifted SlJ AAS}ITO Oesahtsr clayey SAND & GRAVEL (9 =tt,a A 2 lrl c) E TI a L@rim Test Hole Hl4-23 Depth 24.0 feet % kavel 23 % Sard 55 5 Silt& Oay 22 Asetteryftnfts LL Pl Claccfrcatbr Lklid Sl.l AASIITO DIAM ETER 95'2 a.'5 238 l.r9 5n gt1 .rt9 .Oza OF PARTICLES IN iIILLIMETERS PARTTCLE SIZE ANALYSIS CHART Job No: l-1.|01-59.|6 Consuhing Engineers and Geologisls Date: 9/9/83 Fig'ure A1- 13 SLR.1 PARTICLE SIZE ANALYSIS CHART o 2 -ar,tt A z UJ (, tr 4l Oescbdar clayey SAND & GRAVEL L@adon Test Ho] e HM-24 Depth 25.0 feet % Gnwt 30 lB Sard 45 :t Sih & Oay Atterbelg limic Chsificat*rr Desqbdat l-@don I Gntd % Sand 5 Sit& Oay Aubery enits Chssificatin: 25 LL Unified AAS}ITO PI GC (, z o .h z lrl ul A tL lrnined AAS}fTO (, =o o A z u C) E lrl A OeeortsOar Laatbn E Gnvel 5 Sard B Silt & oay Auaberg lLnits Oaaificatirr LL PI rr{d /CA$|TO DIA}IETER 9.52 4J6 23t r.19 5n .gn .r49 .O74 OF PARTICLES IN M ILLIiI ETER S PARTICLE SIZE ANALYSIS CHABT l,lob Nor l-ll0l-5916 Consulting Engineers and Geologists Date: 9/9!83 Frgure A1- 14 SLR.T I A 0 ! a f o :E 0 z t o \. I : t 1200 1600 tao0 1000 {00 a a 3 soo Irl E F o 600 200 Srrnptc o1 claYeY SAND Moleture Conient l5'4 i Unconflncd Comprcrrlvc Strcngth 56 STRAIN (') from re.t h6gs HM-24 at dcptlr 25.0 Natural Dry Denelty 't480 'n4 pcf leet. Psf ba / \ / / / / / 1 I li t -l al I I lt t, I I UNCONFINED COMPRESSION TEST RESULTS Joblrb: l-llol-59]6 Comulting [ngineers and Geobgists Date 9/9/83 Fgure A1-15 9) @ I ,rrl 3 t D 0 -\ { I I 8 c :€-3.t c|i a-c 0 o I I I I 1 500 1,000 sandy CLAY 10,000 hote@ t 00,o00 depth 9'0 feet. - f rom LOAD (psf) test at Sample of Naturat Molsture Content 21 '2 7 Natural Dry Den e ity 105 Pcf. I I I I I I 8 tr o G 1t =0 !,c o (J a- 0 ? 3 4 5 r00 Scmple Natural 500 1,000 r 0,000 LOAD (psf) of sani.y CLAY from t€st hote@ at de'PthStcet. Moicture content l9'3 5 Natural Dry Dendtv --i95 ptf' r 00,o00 pressure due to w3ttlng ater added 6 Consolidation under constant pressure due to w€tting 7 \ \ Water added to sample \ SWELL . CONSOTIDATION TESTS JobNo t-ilol-5916 Date 9/9!83 Frgre Ai-16 sLR-tb I J t D o s'l C I t €lr eJ I I J ! .l ,l .l I I I 8 E : €E o-o Ci o o I I I I I 0 / ? 3 4 r00 Sample of 5 00 r ,000 sandy CLAY LOAD (psf) test hole r 0,000 HM- 3 100,000 at depth 9.0 f""t.from Naturat Molsture Content 12.6 X Natural Dry Density lts pct. I I I l0 I 8/ E o o- :0?lrv ti o e4 I I ls I I, 100 5 00 I ,000 sandy CLAY r 0,000 r 00,o00 aeptn9tcet. LOAD (psf) Sample of - from test holeE at Natural Moicture Contcnt 18.4 g Natural Dry Denrlty -L pcf. Consolidation under constant pressur€ due to wettlng 7, Water added to sample No ch'lllge under conetant preasure due to wettlng Water added SWELL . CONSOLIDATION TESTS JobNo l-1.|01-59.l6 Comulting Engineerr and Gcologitlr Date 9/9/83 U o 'e, I I I I ! t o 0 ') I 1 I 'l I 8 c 3 !- :.E:o- EI o O I I I I 'l I roo Sample Natural 500 I,000 sandy CLAY r 0,000 HM-7 100,000 LOAD (psf) of from test hole at dept6 9'0 .l08 teet. pct.Moisture Content .|8.3 5 Natural Dry Dencity 4 I I 0) 'o x tr o o g o ID t! o o t. 0 e r00 Sample Natunl 500 r.000 sandy CLAY LOAD (p sf) tect hole Na tural r 0,000 HM-l g rt Dry Denrlty 100,000 depth 4. feet. lC9 pcf. ot f rom Moloture Content ]8.1 3 Coneoliiillon under con3tant pressure due to wettlng Water added to sample Swell under constant ,,/ pr"""ure due to wetting 5 a l- I \ I t Water added to sample / SWELL . CONSOLIDATION TESTS JobNb: l-ll0l-59;6 Date: 9,t9/83 Frgure A'l - 18 sLR.8d @ I I I F .o o r!-t c a g C IL I -Consotlfon under constant prescur€ due to wcttlng I \ I Water added to sample q- I 5 ti : 6. ! o-- an c 0 I I I I 0 / ? 3 4 5 6 7 100 500 1,000 sandy CLAY r 0,000 (p sf) test hote HM-21 I O 0,000 depth 4 feet. LOAD Sample of - from at Naturaf Molsture Content 20.1 7 Natural Dry Density iu+pcf. t I |e c o o : o o E o O It Consolldatlon under constant pressure due to wetting Water added to sample lo0 Sample Natural 500 r,oo0 LOAD (psf) 10,000 100,000 ol from test hole- at dePth-fcet. Moleture Content -X Natural Dry Denrlty.pcf. SWELL . CONSOLTDATION TESTS JobNc 1-tlCl-5910 Date 9/9/83 Fipre A1-19 PROJECT:,ta* o*n 'rortr/rr^*, nrn ooo* a,no, ,ro*t, ,tFilt-t- HoLE:H14-4 DATE: 7-14-n? LOCATTON:VAIL, COLORADO PAGE OF 1 A COMPONEN|T B COMPONENT DEPTH +DEPTH + 3 /.14 - /?4 \- /ot /20 .f /g{- t10 \-18 68 ')2/s ' 242 \I 4 .24 /- 2t7 g3 -4? ll r 32/- ?L7 7A -62 /3 1 3dJ - 4Dt 42 - 2/ 39t - 11 3 ?-8 t7 1./1 - +q2 - 2,34 t,413 - s39 -s7 42 2l 63t - s71 34 - 2t 23 6/i - z6+It -?o 2{7/2 - 772 /2?- /20 a?8/4 - 84a tdl - /1t J,Pt(- c34 2d/- /?4 3t ?/6 -,/D22 2t4 - 279 33 ,/oao - /or!.?.{o -uq K ,/a/a - /ot7 4/6 - 4to 3?/o3?- / orL aF4 - J7t 3?/a.Fo - .//27 913 - -t*z 1/,// ?J - /2.J.t t 74 I '76/ ./3 /302 - ,/39d 317 - a12 4{/./{4 - /.1-a3 |ll ?a(- g/D 47 ,/4t 0 \??7 - ,8, 49 /724 - /J2l VI 9ct - )/3 sl - /t/4 g7?- l$a) 5?./4 7?- /72/q73 - 977 t{./gEA - /626 9tt - 982 t1 ,/fl6 - ./gz//aoz - /aoL 57 /414 - /1(t ,/o44 - /D1 / a//1/O - /4-13 ,/a?2 - /obt tl ./4 /6 - /1 Z3 ?77 - r7a 4(,/471 - /-{/,qz.(- *2a r'7 /'/-9/- /{oA \?/3 - 4o3 4,/12 Z ' t17t \tt3 - uxd @ A+ A- B+ B- ORIENTATTON Da@AJ H,/zz- A? /|./LL - SLOPE INCLINOMETER FIELD DATA Job l.lo: 1-1 101- 5915 Date: l0-31-R3 Frgure A1-20 PROJECT: "aH Orn 'rrt{r/rr.u' orn ooo* .' no, ,rorr, ,T7 TEST HOLE: Hil_19 DATE: 7=14-83 PAGE 1 OF 1 LOCATION:VAIL COLORADO A COMPONEN|I B COMPONENT DEPTH +DEPTH + +- /84 /q2 I f 6/-p8 6 - /30 /1/- t71 /30 f '/o-1 /t4 - ssl 306 /o - /42 /94 382 lt i - //?/26 - 114 373 t4'-2P s3 - 110 3qt /(/67 - /-t3 - 337 2?2 rl 3/a - .?a2 - -3Dt 2€2 20 4/7 - ,ta?- 2L3 1t7 22 47?- 172 - 246 2e I 24 ,136 - 57t - 2s8 /?2 26 7//- 7c2 -2i?t7/ 28 7?2 - ?*4 i - 233 /?/ JO t?a - fnt - 21 |tql 12-q_f€- q47 - 278 /?2 34 ?46 - ?37 - 223 /84 3L ?32 - q72 1 s - 32?/8t 33 ,/a36 -,/o27 +- 2.(1 2/2 4a ././ A /- /D?2 M - 271 22? 42 ,//62 - /,/i-t - 288 z,l{ 41 / 22?- /2/8 - 34?3d3 4C /264 - /24/-4tt 3?t 48 /2zg - /2<4 - 384 339 5o /2/3 - ltql - 3t+t3E 52 / 228 - /2/6 - 43?14o 54 //86 - //6t I -63|,tEo a B- COMPONENT aEENr4rIoN A+ A- B+ B- NOz7H -td dlH EA 57 u€s7 SLOPE INCLINOMETER FIELD DATA Job tlo: 1-1 101- 5916 \t.. ? -?t ? - -a - -? Date: l0-31-g3 @ \ , Lolltull|n8 Englnssrs an(r \tcologltrt Figure A1-21 PROJECT: HIGHIANN MFATFS/HIGHIANN PARK SIOPF STARII ITF:'^S: HOLE:Hl'l-21 iocerlor.r,VAIL. COLORADO DATE: 7-14-8? PAGE OF 1 A COMPONEN|T B COMPONENT DEPTH +DEPTH + ?- 27-1 237 t -72 76 _{-2tg t73 -72 8/ 7 - 9.q t2 - Jt2 /ot 7 38 -82 -?t /at // r /33 - t7z -q /8 ,?/- 2t_5 -?.f 2 f/)- ztL -t9 74 /7 241 - 2q2 -i?tz /7 243 ' 2aR - )ao //a 2/2.14 - 2/7 -13 ,/o4 J3 2eb - 2-f6 :102 //o .?{/st - ta2 - ./37 /r'4 27 /st - JdA - 23/236 2q /72 - 9e3 - 3L8 374 3l /2?- t24 - 42?432 33 /13 '2o7 -.;'{2 540 t(- )L3 \t - z1?a5f 37 4o -E4 - 73/736 3?-22 -/7 {- 9to 9tz 4/- t/l t6 \- cq?/ao3 43 - 2D7 /la '892 7al 4{- t.P2 3?9 'qdj 9/a 17 - -?L t 3/?- q.</?-{? .11 - lsa 33?'/da?/o/4 t/' ?<l 3a4 - ,// 71 // E3 :<3 - 281 23d - ./2 /z ,/22 /- 2.<2 2A1 -./272 /284 d7 ' -?aD 2€a - ./ 13?./.11? r-7 ' .q4B 3az ' /23//284 COMPONENT ORIENTATION A+ A- B+ B. DouP il/ll. UP H/LL STDE H/TL SIDE ,ftLL SLOPE INCLINOMETER FTELD DATA Job l.lo: 1-1101-5916 \? a.. a' ,.t?- a !Date, l o-31-83 G"t \ ,LOntulilnt Englneers .ns steologl5Is Figure AL-22 pnb.lecr, ,ra* orn ,nrolt /rr^u,o*n ooo* .,n0, .roor, ,tF TEST DATE: PAGE HOLE:Hn-24 7-14-83 TOCATION:VAIL. COLORADO oFl A COMPONENT B COMPONENT DEPTH +DEPTH + 1 - 2 /Lt /67 \- 4?a 333 4 -4q -/a \',t7a 379 n //7 - /.<?\394 /o /48 - t?,s \-333 36? t2 //7 - /63 \- t37 339 /4 a6 - //4 '-taa 30a ,L 4t -n '2zo 2s€ ./t 43 -?n --t/7 330 2a /28 - t72 - 371 379 22 /7t - 222 --t93 448 21 20/- 24t -402 4tg 24 /?a - 24/- rl24 4/6 29 334 - 27?-f_a 5d/ 30 2t2 -3D -,f63 €?3 32 33?-3P<-t/t 623 -4 423 - 469 -at 24f, 36 524 - 672 - 11 ?24 38 6?2 - 7.<O - 7t/?to 4o atf - 9-<1 - /a-?.9 /a4d 12 92A - ?a8 - /a?4 /ar6 l,l a71 - 9-1n :\- //53 //37 44 ?21 -?70 - /2-f2 /237 4E /a'A -./244 - /334 /332 <e /o 7?-,/,/2,\- /33€/3JA 62 ,/o?2 -.//42 f - /4/9 /42Q azl ,/aa4 - ././ 12 - ./4Af /476 €6 /o77 - /,/,t2 -./sst /54d €t ///2 - t.ts'J - /s/6 /€24 6o /// 7 - //66 - //91 ./daa 62 - //.r8 - /4?a ./taa 44 /a r3 -.//.f2 -./.tt4 /.f2 / a6 /a t4 -./,/tJ -,/12d ,/643 6t /a3t - //82 - /622 ./427 70 ,//50 - /20L - /6/6 /62 / 72 //56 - t20?- -t43i ,/13t 74 //16 'l/90 -/5rZ tfTE 76 /2a4 -,/2!3 t - ./574 /574 B- @oxEN.I A+ A- B+ B. ORIENTATION Dou, H/LL UP H/I.L :i/.oE H//L 3rOE H/// SLOPE INCLTNOMETER FTELD DATA Job |\,lo' t-1101-5910 Consulling Ingineers and Geologisls Date: I n-31-gj Figure 41-23 N o t .-, .,f;C i *,*.P' .,! ,.oH u 4u! ot cc F(J o a,od .-er>!.P!'.' O g -93 "E 5e-5 E lls Es s::i : rE? -"E i€.:'.I 6tA6 '- t).: :.= :. 'E5"* ;98 3' Ee!;" egi ;; ;:Ei f :€'- 3;.9::E ! E.C ! io! .J eF .4 6,< .OC OE4r-co o, o.c o 6 .JC!O EL 6 ]lPr.-ll, o oq,s-o F.-!r.-o>ll)'s <r E.!,d E!, .E or! r-F C>,! r-C .- .- E x L€ .r .t^c .-F ."! x are! l|, o o - oOL .^ a o- -o E6 vt'-I .E. E;3-€ et.;o ord,L u'=i .=3t-s::E O EE ' O ^ t'E h-P.gE-h9'"oFe .F > t -' a, L il, d E.c rU il,; -Eh ".i'E*B€c !t o,E :;L-'988""i :g !t o 6 d A.r !.EE:*e--E.eet8b L.>Er.c'cl>\€ E 8,*o c -bE " g.: I E g ! t o.'o oo xflE b. r q, o q cn.J l--oE €.o'- c, E L.rocirxo ar a, <e'n .Ct! L (lre|!.J !.9:=G E $.1 q,-5,.-'q, e.-e E ttt oEt 9*.e-1.9:R'AE-=--L.'uf oF x9.J < !^L.P, o (^! !arL|!- 9{.9 'E- - r,b3" -"B.:9Eel.g:?i5e:b !.tl j- evlt- -t- cr ot d p!e EI ;;;; ; ,/-79! /Y/ - .Y/dtO \ \ \ \ o\ \ a \ N $ \9 \ t, $ $ \ x N t \s Ss stw \\ \N \.} \ z,l EL eh I {r'' N t E ! E ig 'a,?F cc "\. ({{ |- , $E g.; 6a l-E i9i oor xgru Lo)!, .r 0r fE E;Eg g 'a 6v o 9 rl, c 4 >! 4 99 9 ^ c; d E t€rsE .;rrD!,(|, o or .c ol. o-rE i 3 )l =1 . t JI <F *l .E 'c 3 5l "- i F <t >. >, E -t !L ll ;g i6 cil {l is dE El ..1 >r E (5 Jl .l EE -:- al Hl ;T elE 5l -l i. -l-b -'l .l ., o ..1 til Jl Ft >L t- vl El ?t -g ;tt 6l ., pI EI 3E AF -I eln=N m m *\ .$ rn R P F FS lrrrrltrrrlrttrltrrrlrtlrl * (f) \ 9 f I h \ N $\ N t \ \s $ h ,'9' s e $ rl \)\\ v) N Psorccl Hlohland Pdrk at l. Vail ProJcct No.l - 0t-5916 Borlng No. HP-z Tor.l Dcpth I 18.l Surface El:vatlon ProJect M!n!gcr Fleld Engr ./Gcol. iike A. Brown Ron Holcoi$e Drlll Blg 455 Drlller Steve Gray Depth Log Sarnplc x Rec. RQD Llthology Notes -0 : - :s : lro : - ltt : ='o - -z) : - JIJ I r t [-u t I T r- f- 40 F I t- ['. LD 5/6 8/5 SPT r7 /6 15/6 t3/6 1216 r1/6 Lb sPT 30/4 - - l{. R. ST 300 psl c8 2016 20/6 Auger refusal at depth 30.0 feet. 8e9an to rotary/rock bi t. SPT 5PT 't2/6 l'lt6 tol6 8t6 1016 t3/ 6 c8 SPT 20/6 t0/3 21/6 43/6 c8 1616 2416 Toosoi I CLAY, very sandy, silty to 5Al{0' clayey, fevr gravels, boulders, stlff to very sti ff, noist, brorn (CI-SC) Sedinentary rock fragorents SPT LU SPT Oisplaced 5I LTST0NI, carbonaceous, nl caceous, convol uted, thln'ly bedded,fim to rcdlun hard, moist, dark gr.y (rL-cL) Probable sl lde nass nat€rlal JI CB SPT GRAVEL E SAll0 In CLAY matrlx, large boulders, cobbles, medlum dens€ to dense, wet, broin (GC-SC)5PT PT c8 SAMPLE SYMBOLS C8- Callfornla Barrel - Blows/lnches SPT' Standard Penelt.tlon Test Blors/lnches ST. Thln Walled Shelby Tube NX' Core, dlamcter 2.155 lnches LOG OF EXPLORATION HOLE Drte: 9/14/83 Flgure: A2-z Prorect Hiqhland Park at Y. vall ProJect Manager ---!9LI9.E9"'b€Fleld Engr./Geol. l'li ke A. Brown Drlll Rlg Steve Grny ProJect No. Borlng No. l-Il0l-5916 HP-2 (contlnued)455 Totll Depth I l8.l Drlller Surfacc Elcvatlon Depth Log Samplc * Rec. RQD Llihology Noter 5C : : : r = t_ L I T I T T I r r t- 60 65 10 75 80 85 90 95 100 -cB c8 l616 2416 N. R. sPT 40/6 50/6 - sPT 50/3 sPT s0/4 sPT 68/5 r r/6 l6/4 Sedlnentary and netarprphic rock f ragmnts GRAvtL t SAND continued GRAVEL 0 SAND in CLAY matrix, llrge boulders, cobbles, rcdiun dense to dense, uet, brown (GC-SC ) lgneous, metanprphic and sedinentary rock frdgnents s r3a i{r .rili, l-cS spt cpt SPT SAMPLE SYMBOLS CB- Callfornla Barrel Elors/lnches SPT' Standard Penetratlon Test Blors/ I nches ST- Thln Walled Shelby Tube NX' Core, dlameter 2.155 lnches LOG OF EXPLORATION HOLE Consulting Engineers and Geologists D.rc: 9/14/83 Flgure: AA-3 Protcct Hlohtrnd P.rk at H. Vall ProJcct No. Borlng No. l-ll0't-5916 HP-2 (conttnued) Totll Dcpih I18.'l Surface Elcvetlon ProJect M anager -&!-!9lg9IE Fteld Engr./Geol. illke A' Erown Drlll Rlg 455 Drlltcr.............ry Deprh Log Sernplc Locatlon * Rec. RQo Llthology Notes , too -105 ]ro - -l l5 -rzv : - : r- a - T t- I t-r- F F t- sPT 68/6 |/6 t6/4 Could not get core barrel down hole due to large unstable boulder5 5016 sPr r00/r' SPT GRAVTL & SAI{0 contlnued SPT SHALE, interbedded,'ll9ht gray clay- stone and dark gray, car- bonaceous, ml caceous, claystone and siltstone, hard to very hard, moist ( cL-r,rl ) SPI Total deDth l'18.I feet SAMPLE SYMBOLS C8. Callfornla Earrcl Sloxs/tnch€s SPT'Standard P€nett.tlon Test Slors/tnche ST- Thln Wallcd Shelby Tube NX' Core, dl.mctcr 2.155 inches LOG OF EXPLORATION HOLE Consulting Engineers and Geologisls Date: 9/14/83 Flgure: A2-4 Pror€ct Hlshland Park at H. Va'll Project No.l-l l0r-5916 Borlng No. HP-5 Totrl D€Dth 21.0 Surlrce Elcvrtlon Prorect Manager Ron Holcombe Fl€ld Engr./Gcot. ---Ul^!e-A-!-reu Drlll Rlg 455 Drlllcr Steve Gray DeDth Log Samplc I Rcc. RQD Lllhology Notcr 0 : I - r : . t I -T I T 't0 20 IJ 30 c8 9t6 8t6 Set ho'llow stem auger, began rock bit at depth 7.0 feet cB 30/2 N. R. sPT 2010 r{. R. ,.ffi ti :i9. CLAY, very sandy, silty to S4fl0, clayet few gravels, gtlff to very stiff, nolsl brern (CL-SC) c8 CB GRAVEL t SAll0 in cl-AY mtrix, many large boulders, cobbles, ||Pdlun dense to dense, rnist, brown (GC-SC) sAtlDsTollE, [Ediu to coarse grarned, subangular quartz crystal s, well ceDented, dolomitic cemnt, noderately fractured, high angle (600-800) frdc- tur€s, mtal oxides, very hard, nedium rDist, nhlte to light brown (SP) 5PI NX 95 45 Total oepth 27.O feet SAMPLE SYMBOLS CB- Crllfornh Blrr€l Elons/Inches SPT- Stlndlrd Penetrrtlon Tcst Elors/lnch€ ST- Thln Walled Shelby Tube NX' Corc, dlameter 2.155 inches LOG OF EXPLORATION HOLE Consulting Engineers Dare: 9/14/83 Flgurc: A2-5 ProrGct Hiohlrnd Pdrk at g. Vail ProJcct No.t-l't0l-5916 Borlng No. HP-7 Tot.l Dcpth 2o'8 Surface Elcvatlon ProJect Managet Ron flolconbe Fleld Engr./Geot. fiike A. Srown Drlll Rlg 455 Drlller Steve Gray Depth Log Sample Locailon F Rec RQD Ltthology Notes - - . I I I I r - I I r I q t0 '15 20 25 Eegin rotary at depth 3.5 feet 8e9in core run at depth ll.l feet m CLAY, very sandy, silty to SANo, clayey large boulders, stiff to very stiff, moist, bra{n (CL-SC) SANDSToNE. wel l cemented, dolomitic cement, rnderatelJ fractured, nedi um to coarse grained, subdngular quartz crystals, metal oxides, very hard, n€dlw noist, vhite to light brown (SP) Shale Bed 100 Total oeDth 20.8 feet CB. Callfornla Brrrcl ST- Thln Wallcd Shelby SAMPLE SYMBOLS Tube SPT- Standard P€netr!tlon Tc6t NX' Core, dlameter 2.155 Inchcs LOG OF EXPLORATION HOLE D.trf 9l14/83 Flgure: A2-6 Prot€ct Hichl.nd Park at g. Vall ProJGcr No. Borlng No. Totrl Dspth r-ll0l-5915 62.6 Surlac: Elcvatlon Prorcct Managct Fleld Engr./Geol. Ron Holcorbe lll ke A. Brown HP.IO DrlU Rls 45s Drlller Steve Gray l0 l! 20 25 30 40 45 50 cB 6t6 t?|6 cB 616 6/6 sPr 6/6 17/6 816 ST 500 psi .R. c8 5t6 7t6 sPT ?9/6 t3/6 t3/6 sPT 30/4 - - sPT 38/6 l2ll sPT 38/6 3216 Asphalt, Ease Course, ihn-itade Fill GLAY, very sandyt slltY to 5Aro, cl few gravels, sedim€ntary rock fragment3 very stiff, noist (CL-SC) GRAVEL & SAt{o in CLAY natrlx, large boulders, cobbles, medium dense to dense, moist to wet, broirn (GC-SC) lgneous and n€tamorphic rock fragments Igneous and netatrorphic rock fragmnts SAMPLE SYMEOLS C8' Callfornla Barr€l Elors/lnches SPT' Strndtrd P€nettrtlon Test Elors/ ln.hes ST. Thln Walled Shelby Tube NX' Core. dhmcter 2.155 Inches LOG OF EXPLORATION HOLE Date: 9/ 14 /83 Flgure: 12-7 Pror.ci Highl.nd Park at l. Yall Pror.ct No.l-ll0l-59r6 Borlng No. HP-10 (conttnued) Tot.l Dcpth 62.6 Surfacc Elevatlon Prolect Mlnlger Ron Holcorse Fleld Engr./Geol. rite A. Erown Drlll Rlg 455 Drlller Steve Gray Depth Log Sample , Rcc. RQD Llthology Notcs 50 55 60 o) SPT sPr 9l/6 lt. R. Set hollon stem auger and rotary at depth 52.0 feet De9an t!1 GRAVEL t SND continued Sedlmnterv rock fraoments SAlloSTotlE, [Bdim to coarse grained, subangular quartz and feldspar crystal ni caceous, well cefi€nted, dolomltic cemnt, sllghtly fractured, very hard, n€di un rblst, light gray (SP) 9l 9l Tot l oepth 62,6 feet SAMPLE SYMBOLS C8. Crllfornle Barrcl Slons/lnches SPT' Srandard Penetratlon Tcrt Blofs/lnche ST' Thln Wallcd Shclby Tube NX- Corc, dlrmctcr 2.155 lnchcs LOG OF EXPLORATION HOLE Consulting Ingineers and Geologists D!tc: 9l l4la3 Flgure: A2-8 a t a E f E o o to or rJ) I (./) co or Oi sl o o Ol 1 (\l o |It F tr: =.9 rr)o! 6(, o I o z D o FI *g i !; re A' rE :;E8 I z F U,ttl F &o F E o EI J lr.o E E =p o ;s 3: a I o 0 , f A dr@ oo (Y) rft (o (\l Gl F (\J ; s!'F o c.t ;i;'(o or (f, Or Ct'r lJ) lft (Y)slN-tt\@(\J @ Ctr cl 9N E<to t,L Eg' =tlJ 3o (!, 5. ;3 oorFctooooooo oo ctr O.t $t (\l iij oo 6l(\lGl(nsfu)to@cnF riittttll,ll-l-l ci cL ci cL fi o- c! o.ao- cl 4 o- =====-------- c o I !.o -t , I L tlt A I t s ? ,tr".E srzE ANALys* tl.o*t E irt .D a z Irl I IE t!! PaofoOqr clafey SAND& GRAVEL l,@atim Test Ho] e HP-l Depth 9.0 feet i Grawl 38 ,[ Sard 4l 5 Slh & Oay Atterterg Lnfts qassff,.atlon: 21 LI trnified SC-SG AASTITO OescftOm SAND & GRAVEL I z .t q a z lrl (J ts LI r t@thn Test Hole HP-2 Depth 13.0 feet 5crard 27 5 Sard 60 r Sft&qav l3 Aterbqgrlnic tL Pt Cladtu0m: Lffid Sl.l-Gl.'l AASFITIO Oessbtcr claYey SAND lacarbn Test Ho] e HP-2 Depth 597 feet (, =at,o A F z lrl C, E lrl $ lo o 100 90 EO 70 @ 50 5 (iravel 2'l ,[ Sard 5l 5S&&Oay Aterbelg Enfts Cbeefficatirr 30 20 28 LL t.ffid sc AASfiTO 752 3t.t lg.t DIAMETER 95,2 a.75 238 r.l9 gn 21n .rf9 .074 OF PARTICLES IN IIILLIiIETERS PARTTCLE STZE ANALYSIS CHART Job No: l-l l0]-5916 Da te : 9/9 /83 GoD Conrulting fngineers and Geologists Figure AZ-10 SLR.T ! PARTTCLE t SIZE ANALYSIS CHART OescrteOon claygy SAND I z g' tt c z I tr Test Hole HP-8 Depth 4.0 feet t3 49 % Sih & Gay Atterbqg Lnis Cbsftuthrt Unmea SC-SM AASfITO Desqipddt clayey SAND & QRAVEL I z o 6 I z trJ I E o Locador Test Hole HP-10 Depth 40.0 feet % Gravd 30 E Sard 50 % Sft&qay 20 AtabqsLnits LL Pl Oassffcatin: unffied SC-SM AAS}fTO Descrbddr clayey SAND (9 z tt o A F z t{E' E trl A L@tin Test Hole HP-ll Depth 9.0 feet x Gnvel 16 5 Sand 34 tsft&Oav 48 Aterberg Enfc LL Pl Oaedlcatlorr Un4 SC AASHTO DIAMETER OF 1.76 2,9 r.r9 590 Zn .ra9 .O71 PARTICLES IN MILLIIIETERS PARTICLE SIZE ANALYSIS CHABT Job No: l-'1.l01-5916 Consulting Engineers and Geologists Date: 9/9/83 Fi5'ure A2- 1l SLR.I (9 ; c E:o a E L 0 lr 't I ' ^l lo I I 8 E!3l a.!t o-a' C 0^OC I I I I I I 100 Sample of 500 I,000 clayey SAND LOAD 10,oo0 (psf ) test hoteE at r 00,000 depth l3'0 feet.from Natural Molsture Content ll '8 5 Naturat Dry Density l ll pcf. I I x c o o .o o o E 0 o It o ? 3 100 500 1,000 r 0,000 r 00.000 LOAD (psf) Sample ol sandy CLAY from tesr hole, HP-3 at depth4feet. Natural Molcturc Content 13. 9 g Natural Dry Denrlry. I l7 pcf . .Coneolidation under constant // pressure due to wettlng ./4 lVater added to sample undet conStant pressrlre due to wettlng Water added to sample JobNc l-l'i0l-59.l9 SWELL . CONSOLIDATION TESTS Date 9/9/E3 Conrulting [ngineerr and Geobgislr e, I , D o EI c E L c lL ,' ,4 lo I I 8/ ti g2 E:.tr = ]t o.--o- E 34 I I I I I 100 Sample of 500 I,000 sanC-v CLAY LOAD (psf) 10,0o0 HP-4 100,00 0 depth 4'0 feet.from test hole at Naturat Moisture Content 14'I 5 Natural Dry Densiry il3 pcf. 1 I I I Dq tt o a,.E 0 6 c 0 (J ls 0 ? 3 4 5 6 loo 500 1,O00 sandy CLAY l0,000 100,000 LOAD (psl) Sample ol from test hol..HP-5 at depth 9'0 feet. Naturat Mole ture Content i7,3 % Naturat Dry Denrlty ]02 pcl. , Consolidation under constant / pr.""ure due to wetting 7 L t Water added to sample ConsolldElon under conotant presaure due to w€ttlng ater added to sample Joblrb: l-1l0.i-59.i6 SWELL . CONSOLIDATION TESTS Dare 9/9/BJ Corrultiry Engineerr and Geologists D , a o E-l e2 I F I o lr. a9 -9 ,I I 'l o I I I !e, ; :?a-.lt- = r.?O:-rl F 34 I l5 I I I r00 Sample of 500 I,ooo sandy CLAY LOAD (pef) 10,ooo hole HP-6 at I OO,O00 depth 4'o feet.from test Naturat Molsture Content 14.9 5 Natural Dry Denslty ilt pcf. t I I I r€ c!o !t : o a tr 0 o ls 0 a 3 4 5 6 7 100 500 1,o00 sandy CLAY I O,OOO 100,o00 tn dcpth. 't'u feet. LOAD (psf) Scmple of from test trole-HP4 at Natural Molcture Content .|3.5 5 Naiurat Dry Denrlty ]09 pcf. / Consolidation under constant pressure due to wetting F \ Water added to e ampte I Consollillon under constant pressure due to wettlng Water added to sample SWELL - CONSOLIDATION TESTS JobNe i-I10.|-59.|6 Comulting Engineers rnd Geologists Date 9/9i83 A2-74 I o I I I 'lo I 8/ t o :e o '!t : gi3 E 0 o4 I I ls I \ I loo 500 r,000 sanCy CLA,Y 10,000 lo0.0oo (p sf) test hole HP-]0 at depth .l0.0 feet. LOAD Sample of from Naturat Moisture Content 12.5 x Naturat Dry Denelty lll pcf. I I l I I =It) 3 g, IR o 6 ! 0 a c o (J I I I I 3 0 / ? 3 4 100 500 I,000 sandy CLAY 10,000 (psf) tesr hole HP-1] .t r 00,000 depth -j:.!l feet. LOAD Sample ol from Naturrt llolrture Contentl .16. I x Naturat Dry Dcnelty '107 pcf. Swell under constant pressure due to wetting I I \I \ I Water added io sample - Coneolltlon under constrnt pressure due to wettlng Water added to sample JobNo i-ll0l-59i6 SWELL . CONSOLIDAtrION TESTS Date: 3i9!83 Consulting Engineers and Geologists SLR.Ed APPENDIX B PRELIMINARY EARTHI,IORK SPECIFICATION OVERLOT GRADING APPENDIX B GENERAL A soils engineer shall be the owners representative to control the earthwork placement, moisture content and compaction. The soils engineer shal l approve the materials and the methods of placing the compaction and shall give a written approval of the cornpleted fil l. The fill should be placed and compacted as follows: CLEARING AREA TO BE FILLED AlI timber, logs, trees, brush and rubbish shall be otherwise disposed of. Frozen materi als shal I be by the owner or his representative, stockpiled until SCARIFYING AREA TO BE FILLED removed, piled or burned or removed, or when directed t hawed . All vegetable matter and frozen material shall be removed frcrn the surface upon which the fill is to be placed and the surface shall then be plowed or scarjfied to a depth of at least six (6) inches, and smoothed untjl the surface js free from ruts, hummocks or other uneven features wtrich wouid tend to prevent uniform compaction by the equipment to be used. Where fills are made on hillsides or slopes, the slope of the original ground upon which the fill is to be placed shal'l be plowed or scarified deeply, or where the slope ratio of the original ground is steeper than 5 horizontal to 1 vertical, the bank shall be stepped or benched (see Figure 6). Ground slopes which are flatter than 5 to I shall be benched when considered necessary by the soils engineer. COMPACTING AREA TO 8E FILLED After the foundation for the fjll has been cleared, any frozen material removed and plowed or scarifjed where necessary, jt shall be disced or bladed until jt is uniform and free from large clods, brought to the proper mojsture content and compacted to a density and moisture content as specified below for the placement of fil) layers. FILL MATERIAL Materials for the fill consist of materials selected or approved by the soils engineer. The materials used shal I be free from vegetab le matter, frozen material and other deleterious substance and shall not contain rocks or lumos having a dianeter of more than six inches. Grading plans are not available at this time, however, based on the field and laboratory results, soils anticipated to be encountered in the cut are from three of the groups ljsted on Table I. The soi'l groups, soils and Un ified Classification of the soils encountered are as follows: B-I LOl.l EXPANSIVE COHESIVE SOILS (GROUP I) SAND, very clayey (SC) CLAY, sandy, s ilty (CL) FINE GRAINED COHESIONLESS SOIL (GROUP III) SILT, sandy to clayey (ML) COARSE GRAINED COHESIONLESS SOILS (GROUP IV) SAND, sjlty (SM) It should be noted the soils described comprise the surficial soils at the site, and when these materia1 s are placed in the fill sectjons there will be a mixture of these soils. However, the mixtures of these soils will be within the groups of soils listed above and the applicable specification will be used from Table I. DEPTH AND MIXING OF FILL LAYERS The selected fil I material shal I eight jnches loose thjckness and Each layer shal1 be spaced evenly spreading to insure uniformity of MOISTURE CONTENT be placed in layers, which shall not exceed when comoacted shall not exceed six inches. and shall be thoroughly blade mjxed during the material in each layer. Moisture content will be controlled as a percentage deviation from optimum. Optimum moisture content is defined as the moisture content corresponding to the maximum dry density of a laboratory cunpacted sample performed according to ASTM D-1557. The contractor may be required to add the necessary moisture to the backfil I material in the excavation if, in the opinion of the sojls engineer, it is not possible to obtajn uniform moisture content by adding water to the fill surface. Additionally, the contractor sha11 not place backfil I material which exceeds the maximum mojsture content specification, unless the material is left to aereate or blended with dri er material to achieve the specified moisture specification. The mojsture content specifica- tions for the groups of sojls that will be placed in the structural areas are as follows: LOI.J EXPANSIVE COHESIVE SOILS (GROUP I) Moisture -2% to 4% from OPtimum FINE GRAINED COHESIONLESS SOIL (GROUP III) Moisture -3% to 0% from 0ptimum COARSE GRAINED COHESIONLESS SOIL (GROUP IV) + 3% from Optimum B-2 l''lo isture DENSITY CONTROL Density will .be controlled as a range of percentage from maximum density. Maximum density is defined as the highest possible dry density attained in a laboratory compacted sample performed according to ASTM D-1557. The contractor may be required to scarify and recompact backfill material which has been compacted greater than the specifications for cohesive soils, (Group I, Group II soils). After each layer has been placed, mixed and spread evenly, it shalI be thoroughly compacted to the following specifications for each soil group encoun- terecl : LOl.l EXPANSIVE COHESIVE SOILS (GROUP I) Structural Fill Compact ion Cormon Compact ion 85t FINE GRAINED COHESIONLESS Minimum SOIL (GROUP III) 89% to 96?{ Fill Structural Fi 1l Compact ion 92% Minimum Common Fi I I Compact ion 85% Minimum COARSE GRAINED COHESIONLESS SOILS (GROUP IV) Structural Fi I I Compact ion 95% l'|inimum Common Fill Compact ion COMPACTION OF FILL LAYERS 90% Minimum Compaction shal I be by sheepsfoot ro11ers, segmented steel wheeled rol1ers, pneumatic tired rollers, smooth drum steel rollers, vibratory rollers or other types of suitable compaction equipment. We recommend a smooth drum or pneumatic tjre roller for granular soils and a sheepsfoot or segmented roller for cohesive soils. Compactjon shall be accomplished while the material is at the specified moisture content. Compaction of each layer shall be continuous over its entire area and the compaction equipment shall make sufficient trips to insure that the required density has been obtained. B-3 COMPACTION OF SLOPES Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable eguipment. Compacting operations shalI be continued untjl the slopes are stable, but not too dense for planting, and when there is no appreciable amount of loose soi'l on the slopes. Compacting of the slopes may be done progressively in increments of three to five in fill height or after the fill is brought to its total height if approved by the soils engineer. FIELD TESTING OF DENSITY AND MOISTURE CONTENT Field density and moisture tests shall be made by the soils engineer of each layer of fill. Sufficient tests wi ll be made to determjne the adequacy of the fill. The frequency of testing will be determined by the soils engineer in the field, depending on the conditions encountered. fJhere sheepsfoot ro1- lers are used, the soils may be disturbed to a depth of several inches. Den-sity tests shall be performed by ASTM D-1556 and ASTM D-2216 with four or six inch sand cone, or ASTM D-2292 and D-3017 wjth nuclear density devices and methods. FINISHED SLOPES AND ELEVATIONS The fill operations shall be continued jn above until the fill has been brought shown on the accepted plans. SEASONAL LIMITS six inch compacted layers as specified to the finished slooes and elevations No fill materia1 shall be placed upon frozen subgrade, nor p1 aced' spread or rolled whjle it is frozen or thawing or during unfavorable weather condi-tions. When the work js interrupted by heavy rain, snow or frost penetration, fill operations shall not be resumed until the soi1s engineer indicates that the moisture content and density of the previously p'l aced fil l are as specified. Note 1: This specification complies with Controlled Earthwork Specifications, FHA Data Sheet 79G, Sectjon K, dated June 1973, except for special provisions noted herein. Note 2: The contractor shal 1 place moderate to highly expansive soils toward the back lot lines utilizing the more favorable sojls under and adjacent to building foundation and slab structures and driveways. Note 3: Strippings shall be stockpiled as directed by the owner. Note 4: See attached Table l. B-4 SUMMARY 0F C0MPACTI0N AND M0ISTURE REqUIREMENTS LOt.l EXPANSIVE COHESIVE SOIL (GROUP I ) Unif ied Soils Cl assif ication (cL)-LL<35 7<Pt<20 50%<-#200<100r (sc) -LL<3s 7<Pr<20 251 <-#200<50% (CL-ML) LL<28 4<PI<7 50x<-#200< 1009 (sc-sM) LL<28 4<Pr<7 25?(<-#200<50% (GC) - tt200 > L2% -#4 < 50% (GM) - #200 > 12% -#4 < 50/ (GC-GM) - #?00 > L2% -#4 < 5M Structural Fill Compactjon-891 -961 Moisture - + -2I to +4% from 0pt'imum Conmon Fil I Compactjon - 85fl Minimum Moisture - N/A I{ODERATE TO HIGH EXPANSIVE, COHESIVE SOIL (GROUP II) Unified Soils Classification (sc) LL > 35 Pr > 20 (cL) -LL>35PI>20 (cH) -LL>50 B-5 TABLE I Structural Fi I I Compact ion - 87X - 93t Moisture - 0l to +41 from Optimum Conmon Fill Compaction - 85* Minimum l'loisture - N/A FINE GRATNEp C0HESToNLESS S0IL (cRoup rrr) Unified Soils Classification (ML ) (MH ) LL< 50 LL> 50 PI< 20 PI> 20 Structural Fill Common 92fl Minimum 0X from Optimum Fill Compaction - 85X Mjnimum Moisture - N/A coARsE GRAINED CoHESToNLESS S0ILS (GRoUP IV) Unif ied Soi ls Classif ication Compact ion l4oisture - -3% to (sc) (sM) (sc- sM ) (sP) (sr,t ) (Gc ) (Gr4) -#200 < 251 -#4 > 50% -#200 < 25r -#4 Z sW -#200 < 25' -#4 > 501 -#200 < 5% -#4 > 5M -#200 < 5% -#4 > 50X -#200 < 2s* -#4 < sor -#200 < 25r -#4 < 501 B-6 (GC-GrJr) - -#200 < 251 -#4 < 50r (Gn) - -#2oo < 5r -#4 < 50' (ew1 - -#200 < sr -#4 < 50* Structural Fill Compaction - 951 Minimum l4oisture - j 3f from Optimum Cormon Fill Conpaction - 90f Minimum l,,loisture - N/A t{ote: The conpaction and misture requirements are based on I'lodified Proctor density (ASTM D-1557). B-7 .t4