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HomeMy WebLinkAboutElk Meadows Soils Report.pdf 1-ISE wortii-I';t I,ik (3cr,r 'cI if LI, Ey.. GeStH eCh 5020 54 Mow:')70-445-7',6'S tr 1 0;td [ HEPWORTH-PAWLAK GEOTECHNICAL ]-", 970.',14 ti-]5.] PRELIMINARY SUBSOIL STUDY FOR FOUNDATION DESIGN PROPOSED RESIDENCES LOTS 1, 2 AND 3, ELK MEADOWS SUBDIVISION BUFFEHR CREEK ROAD VAIL, COLORADO JOB NO. 114 086A APRIL 18, 2014 PREPARED FOR: ELK MEADOWS DEVELOPMENT, LLC ATTN: SHARON COHN 141 E. MEADOW DRIVE, SUITE 211 VAIL, COLORADO 81657 _Pi o Prier 303-841-7119 • C lorahlin Sprin4!s 719-633-5562 • SII1'erth( !nu 970-46S-14), 4I k • TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY - I - PROPOSED CONSTRUCTION - 1 - SITE CONDITIONS - 2 - FIELD EXPLORATION. - 2 - SUBSURFACE CONDITIONS - 3 - FOUNDATION BEARING CONDITIONS 4 - DESIGN RECOMMENDATIONS - 4- FOUNDATIONS - 4 FOUNDATION AND RETAINING WALLS - 5 - FLOOR SLABS - 7 - UNDERDRAIN SYSTEM - 7 - SITE GRADING - 8 - SURFACE DRAINAGE - 9 - PAVEMENT SECTION - I0 - LIMITATIONS - 1 I - FIGURE 1 - LOCATIONS OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURES 4 and 5 - SWELL-CONSOLIDATION TEST RESULTS FIGURES 6 and 7- GRADATION TEST RESULTS FIGURES 8 - TYPICAL BOULDER WALL DETAIL TABLE I- SUMMARY OF LABORATORY TEST RESULTS Job No. 114 086A G _ p,ech PURPOSE AND SCOPE OF STUDY This report presents the results of a preliminary subsoil study for proposed residences to be located on Lots I, 2 and 3, Elk Creek Meadows Subdivision, Buffehr Creek Road, Vail, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for the foundation design. The study was conducted in general accordance with our proposal for geotechnical engineering services to Elk Creek Development, LLC dated March 24, 2014. Potential geologic hazards at the site have been addressed by others and are beyond the scope of this report. A field exploration program consisting of exploratory borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION A single family residence is planned on each of the three lots, see Figure 1. A residence is also planned on Lot 5 to the west but was not included as part of this study. The residences will be two story wood frame structures with the lower level retaining cut of the hillside slopes. Ground floors will be slab-on-grade. Grading for the structures is assumed to be relatively minor with cut depths between about 3 to 8 feet. We assume relatively light foundation loadings, typical of the proposed type of construction. There will be an access drive from Buffehr Creek Road to the residences. As part of the site grading there may be boulder walls retainin{; cut and f11 up to 6 to 8 feet high. Joh No, 114 086A Gtech - 2 - When building location, grading and foundation loading information have been developed, we should be notified to re-evaluate the recommendations presented in this report. SITE CONDITIONS The lots are vacant and the ground surface was covered with about 3 feet of snow at the time of our field exploration. There is an existing residence on Lot 4 with an address of 1630 Buffehr Creek Road. The terrain consists of a narrow valley bottom with moderately steep side slopes. Lot 1 is located on the south valley side where the terrain slopes down to the north, and Lots 2 and 3 are located on the north valley side where the terrain slopes down to the south. Slope grades range from about 25 to 35% on the valley side slopes and about 6 to 8% in the valley bottom. Elevation difference across each assumed building area ranges from about 8 to 12 feet. The access drive will be located in the relatively flat bottom of the valley. Vegetation below the snow cover consists of thick grass with aspen trees on the valley side slopes. There are several scattered boulders on the ground surface. FIELD EXPLORATION The field exploration for the project was conducted on April 10, 2014. Three exploratory borings were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. One boring was drilled on each of the three lots and the boring number corresponds with the lot number. The borings were advanced with 4 inch diameter continuous flight augers powered by a truck-mounted CME-45B drill rig. Access consisting of snow removal, some topsoil removal, and towing the truck-mounted drill rig with the backhoe was needed to access the boring locations. The borings were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Samples of the subsoils were taken with IA inch and 2 inch I.D. spoon samplers. The samplers were driven into the subsoils at various depths with blows from a 140 pound Ju No. t140 6A GeSt di - 3 - hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site are shown on Figure 2. The subsoils encountered consisted of nil (after being removed) to about 3 feet of organic topsoil overlying medium stiff to stiff, sandy to very sandy silty clay with scattered gravel. The silty clay soils were underlain at depths from about 3 to 8 feet by medium dense, silty to very silty sand and gravel with cobbles and possible boulders that extended down to the maximum depth drilled of 26 feet. The approximately 3 feet deep topsoil layer had been removed at the Borings 2 and 3 locations for the drill rig access and the topsoil layer is not shown on the boring logs. Drilling in the medium dense granular soils with auger equipment was difficult at times due to the cobbles and possible boulders and drilling refusal was encountered in Boring 3 in the deposit. The sand and gravel soils occasionally contained some sandy silt and clay zones or layers. Laboratory testing performed on samples obtained from the borings included natural moisture content and density, gradation analyses, and Atterberg limits. Results of swell- consolidation testing performed on relatively undisturbed drive samples, presented on Figures 4 and 5, indicate generally moderate compressibility under conditions of loading and wetting with a nil to low hydro-compression potential. Some of the more granular soil samples may have been partly disturbed due to the rock content. Results of gradation analyses performed on small diameter drive samples (minus 1 1/2 inch fraction) of the natural granular subsoils are shown on Figures 6 and 7. The Iaboratory testing is summarized in Table 1. Joh No. 114 OR(A Gtech -4 - No free water was encountered in the borings at the time of drilling or when checked 6 days later and the subsoils were slightly moist to moist. FOUNDATION BEARING CONDITIONS At assumed excavation depths for the residences, we expect the subgrade soils will transition from the silty sand and gravel to the more compressible silty clay soils. Spread footings bearing on these soils should be feasible for foundation support of the buildings with some risk of settlement. The risk of settlement is due primarily to the variable bearing conditions and the more compressible nature of the silty clay soils. Extending the footings down the bear entirely on the sand and gravel soils would provide a Iower risk foundation. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the building be founded with spread footings bearing on the natural soils with some risk of settlement. The design and construction criteria presented below should be observed for a spread footing foundation system. I) Footings placed on the undisturbed natural soils should be designed for an allowable bearing pressure of 1,500 psi. Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be about 1 to I%2 inches for the assumed light loadings. Footings placed entirely on the underlying sand and gravel soils can be designed for an allowable bearing pressure of 2,500 psf and settlements are expected to be up to about 1 inch for the assumed light Ioadings. We should review Job No 114 0€GA G ep. h 5 - the settlement potential when foundation Ioadings are available and make recommendations to mitigate the settlement if needed. 2) The footings should have a minimum width of 18 inches for continuous walls and 2 feet for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 48 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be well reinforced top and bottom to span local anomalies and better withstand the effects of some differential settlement such as by assuming an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should also be designed to resist lateral earth pressures as discussed in the "Foundation and Retaining Walls" section of this report. 5) The topsoil and any loose or disturbed soils should be removed and the footing bearing IeveI extended down to the firm natural soils. If the footings are designed to bear entirely on the sand and gravel soils all silty clay soils should also be removed. The exposed soils in footing area should then be adjusted to near optimum moisture content and compacted. If water seepage is encountered, the looting areas should be dewatered before concrete placement. 6) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions. FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are Iaterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pcf for backfill consisting of the on-site soils. Cantilevered retaining structures which are separate from the main buildings and can be expected to deflect sufficiently to mobilize Job No. I I 0 6A Gtech - ti - the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 45 pcf for backfill consisting of the on-site soils. The backfill should not contain topsoil or oversized rocks. All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. Backfill should be placed in uniform lifts and compacted to at least 90% of the maximum standard Proctor density(SPD) at a moisture content near optimum. Backfill in pavement and walkway areas should be compacted to at least 95% SPD. Care should be taken not to overcompact the backfill or use large equipment near the wall, since this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill should be expected, even if the material is placed correctly, and could result in distress to facilities constructed on the backfill. Use of a select granular import material such as road base and increasing compaction to at least 98% SPD could be done to reduce the settlement potential. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.40. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 375 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral Ioads Job No. 1 4 08(A Gg tG-ch - 7 - should be a suitable granular material compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The natural on-site soils, exclusive of topsoil, are suitable to support lightly loaded slab- on-grade construction. There could be some slab settlement in areas that transition the assumed different soil types at subgrade. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4 inch layer of free-draining gravel should be placed beneath basement level slabs to facilitate drainage. This material should consist of minus 2 inch aggregate with at least 50% retained on the No. 4 sieve and less than 2% passing the No. 200 sieve. All fill materials for support of floor slabs should be compacted to at least 95% of maximum standard Proctor density at a moisture content near optimum. Required fill can consist of the on-site granular soils devoid of topsoil and oversized rocks, or a suitable granular material such as road base can be imported. UNDERDRAIN SYSTEM AIthough free water was not encountered during our exploration, it has been our experience in mountainous areas and where clay soils are present that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can also create a perched condition. We recommend below- grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. Job No. 114 086A G 1&&tech $ - The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free-draining granular material. The drain should be placed at each level of excavation and at least 1 foot below Iowest adjacent finish grade and sloped at a minimum 1% to a suitable gravity outlet or sump and pump. Free- draining granular material used in the underdrain system should contain less than 2% passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least I%2 feet deep and covered by filter fabric such as Mirafi 140N. SITE GRADING The risk of construction-induced slope instability at the site appears low provided the buildings are located as planned and cut and fill depths are limited. We assume the cut depths for the basement level will not exceed one level, about 10 feet. Embankment fills should be limited to about 8 to 10 feet deep and be compacted to at least 95% of the maximum standard Proctor density near optimum moisture content. Prior to fill placement, the subgrade should be carefully prepared by removing all vegetation and topsoil and compacting to at least 95% of the maximum standard Proctor density. The fill should be benched into the portions of the hillside exceeding 20%grade. Boulder retaining should be feasible at the site with proper design and construction. The boulder walls should be designed as gravity retaining structures. A typical detail of the recommended boulder wall design is attached as Figure 8. The boulder walls should be limited to 8 feet in height. The boulders for the walls should have an embedment depth into the subgrade at least I'/ feet. The boulder wall subgrade should be compacted to the placement of the boulders. A subdrain should be provided behind the walls. The walls should be battered back at V. Horizontal to 1 Vertical or flatter. Backfill of the boulder walls can consist of the on-site predominantly granular soils and should be compacted to at least 95% SPD neat optimum moisture content. Job No. 1 1 4 086A Gh - 9 - Permanent unretained cut and fill slopes should be traded at 2 horizontal to 1 vertical or flatter and protected against erosion by reve{.,etation or other means. The risk of slope instability will be increased if seepage is encountered in cuts and flatter slopes may be necessary. if seepage is encountered in permanent cuts. an investigation should be conducted to determine if the seepage will adversely affect the cut stability. We should review the site grading plans prior to construction. SURFACE DRAINAGE Positive surface drainage is an important aspect of the project. The following drainage precautions should be observed during construction and maintained at all times after the buildings has been completed: I) Inundation of the foundation excavations and underslab areas should be avoided during construction. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at Ieast 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90% of the maximum standard Proctor density in landscape areas. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first l 0 feet in paved areas. Free-draining wall backfill should be capped with filter fabric such as Mirafi 140N and about 2 feet of the on-site finer graded soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be Iocated at least 5 feet from foundation walls. Job No. 114 056A Ge tech • - 10 - PAVEMENT SECTION We understand asphalt pavement will probably be used for the access drive. Grass Pave 2 may be used at the end of the access drive for a fire truck turn-around area. Traffic loadings for the drive have not been provided but are expected to be light and typical of the proposed development. We assume a traffic loading 18 kip equivalent daily Ioad application (EDLA) of about 15. The subgrade soils encountered at the site will probably consist of the fine grained, sandy to very sandy silty clay which is considered a relatively poor support for pavement sections. We estimate a Hveem stabilometer"R" value of about 8 for the subgrade soils. The soils are moderately susceptible to frost heave. Based on our experience, an 18 kip EDLA of 15, a Regional Factor of 2.25 and a serviceability index of 2.0, we recommend the minimum pavement section thickness consist of 4 inches of asphalt on 9 inches of base course. In tight turning areas or areas of regular truck traffic, such as for trash pick-up, a concrete section consisting of 6 inches of concrete on 4 inches of base course should be considered. The asphalt should be a batched hot mix, approved by the engineer and placed and compacted to the project specifications. The base course should meet CDOT CIass 6 specifications. All base course and required subgrade fill should be compacted to at least 95% of the maximum standard Proctor density at a moisture content within 2%of optimum. Concrete should have a minimum 28 day compressive strength of 4,500 psf and be air entrained. Required fill to establish design subgrade level can consist of the on-site soils or suitable imported granular soils approved by the geotechnical engineer. Prior to fill placement the subgrade should be stripped of topsoil, scarified to a depth of 8 inches, adjusted to near optimum moisture and compacted to at least 95% of standard Proctor density. In soft or wet areas, the subgrade may require drying or stabilization prior to fill placement. A geogrid andor subexcavation and replacement with aggregate base soils may be needed for the stabilization. The subgrade should be proofrolled. Areas that deflect excessively Job No. 114 0 (A Gtech - 11 - should be corrected before placing pavement materials. The subgrade improvements and placement and compaction of base and asphalt materials should be monitored on a regular basis by a representative of the geotechnical engineer. If Grass Pave 2 is used for the fire truck turn—around area at the end of the drive, we recommend a minimum 12 inches of CDOT Class 6 or Class 2 base course be provided below the material. The subgrade should be stabilized if needed, as discussed above, prior to placing the base course. Once traffic loadings are better known, we should review our pavement section thickness recommendations. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure I, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during Joh No. 114 086A G ph - 12 - construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAW , K G61414CAL, INC. pEir • 4 . + . n ' •, ;,�s David A. Young, P.E. 11111"--/ k -/ • Reviewed by: te ,.• A`�►� ihtlNHr��� Steven L. Pawlak, P.E. DAY•ksw cc: Elk Meadows Development Brian Recliner (briars(' salaris .ail.c gym) • \*.'....*C‘441114 -''''•••„,,_. I APPROXIMATE SCALE 1 1" 60' \........................7...... Z ` W Lu \\ \ 1 � — - 1 11 1 1 / BO NG11 l I I -- LOT it I I1 I 1 ! I /� \� 1 1 1 Q l I 1 LOT t1 1 1 I I I 1cr. 1 1 I �! I / 1 1 1 + w `'� _ wI ! / �' 1 r� °�' o "�_ / 1wwU,• _ � -1 0 l 11 / yy(ORIN 2 \\ L- .� EPSM,N — _ _ 610 w I1 / - _ w 11 /_. / 1 rfr _ I w Ca 1/ ! / j II w N CP 1 (31 a ! jl/ I , I Iii LCbT 3 ! ! I I I > / �\ I! I! !I 1! 1 o� �// 1 \0 / 1 / 1 I 83 / / / I I • 0 (') 40 I I I /BORING 3 �� 1 ! / 1 / U TRACT 1 I I I 11 / 0 I ! to LOT 4 Oa_ 0 co M m EXISTING CABIN (1630 // 4305 ► BUFFEHR / / CREEK / ROAD) / I TO LOT 5 I 1 H 114 086A LOCATIONS OF EXPLORATORY BORINGS I Figure 1 HEPWORTH-PAWLAK GEOTECHNICAL BORING 1 BORING 2 BORING 3 LOT 1 LOT 2 LOT 3 ELEV 8320' ELEV.= 8316' ELEV.= 8312' - 8320 8320 — I011 — — A, 4 12 — 8315 12/1217.1 8315 — I WC= — DID=106 — _i - 0I 14/12 — - 8310 30/12 WC=5.2 8310 Om WC=8.6 h4w43 _ IPDD=117 -200=9 - - �00=39 PI=NP 5/12 — Olt--- LL=25 I WC=16.5 — PI-4 ' V DD=108 — • 13/12 -200Q51 8305 32+'12 WC=4.9 8305 Q) — , ' WC=8.0 -200=29 — a) L- t DD=121 . u_ c — �' • 14/12 — c o — WC 36 _ O — ' el -200 30 — .. 26/12 a) Lu 83008300 w . ' 30/12 — ;• WC=10.5 • ` — DD=116 — -200=60 13/12 - - WC 5.6 — -- 51/12 18/12 -200+4 21 315 — 8295 t WC=3.3 8295 _ +4=35 -200=26 — 0 — . 10/6,20/0 8290 8290 8285 8285 • Notes: 1) Explanation of symbols is shown on Figure 3. 2)Topsoil layer about 3 feet thick removed at Borings 2 and 3 prior to drilling of borings. H 114 086A LOGS OF EXPLORATORY BORINGS Figure 2 HEPWORTH•PAWLAK GEOTECHNICAL LEGEND: 0 TOPSOIL; organic silty clay, soft, wet, black. About 3 feet thick topsoil layer at Borings 2 and 3 had been removed prior to drilling the borings. CLAY(CL); silty, sandy to very sandy, medium stiff to stiff, moist, brown, low plasticity. L�• SAND AND GRAVEL(SC-GC);with cobbles, possible boulders, silty to very silty, occasionally clayey, some sandy silt and clay zones, medium dense, slightly moist to moist, mixed brown, low plastic fines, rocks are primarily subangular. jiRelatively undisturbed drive sample; 2-inch I.D. California liner sample. 11 Drive sample; standard penetration test (SPT), 1 3/8 inch I.D. split spoon sample, ASTM D-1586. 4/12 Drive sample blow count; indicates that 4 blows of a 140 pound hammer falling 30 inches were required to drive the California or SPT sampler 12 inches. ter- Practical drilling refusal. —► Depth at which boring had caved when measured 6 days after drilling. NOTES: 1. Exploratory borings were drilled on April 10, 2014 with 4-inch diameter continuous flight power auger. 2. Locations of exploratory borings were measured approximately by pacing from features shown on the s to plan provided. 3. Elevations of exploratory borings were obtained by interpolation between contours shown on the site plan provided and checked by instrument level. The ground elevations at Borings 2 and 3 were adjusted for the removed topsoil. 4. The exploratory boring locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory boring logs represent the approximate boundaries between material types and transitions may be gradual. 6. No free water was encountered in the borings at the time of drilling or when checked 6 days later. Fluctuation n water level may occur with time. 7. Laboratory Testing Results: WC = Water Content (%) DD = Dry Density (pct) +4 = Percent retained on the No. 4 sieve -200 = Percent passing No. 200 sieve LL = Liquid Limit (%) PI = Plasticity Index (%) NP = Non-Plastic 114 086A cotZtech LEGEND AND NOTES Figure 3 HEPWORTH•PAWLAK GEOTECHNICAL Moisture Content =- 17 1 percent Dry Density = 106 pcf ! Sample of:Sandy Si ty Clay From. Boring 1 : 5 Feet 0 1 ttH4TT . Compression w _1 upon 3 l I I Iii wetting b 0 4 • 5 I1 1 0.1 1.0 10 100 APPLIED PRESSURE (ksf) I Moisture Content = 8.6 percent Dry Density 117 pc! I I I I I Sample of:Silty Clayey Sand with Gravel f From: Boring 1 at 10 Feet 0 j 1 I I c . Y I III 2 Compression c upon r 3 I wetting c O U 4 , I 5 I I 0.1 1.0 10 100 APPLIED PRESSURE (ksf) H 114 086A Ge tech SWELL-CONSOLIDATION TEST RESULTS FIGURE: 4 ArORT'H-PAWLAK GEOTECHN' Moir.ure Content c 8.0 percent Dry Density = 121 pcf Sample of:Silty Clayey Sand with Gravel III From: Boring 1 at 15 Feet 0 , ------T1-1-----CH0, 1 II 1 -....,,,,,....N.x,\ 1 2 O I I Compression coI I upon ua 3 wetting ,_ , 5 1 0.1 1.0 fa 100 APPLIED PRESSURE (ksf) I I Mois.ure Content= 16,5 percent Dry Density = 106 pct I Sample of:Very Sandy Silty C.ay From: Bor:ng 3 at 4 Feet 0 I I 1 1 1I , I ' 1 I I 2 I - , I Compression ' rn I upon 3 �� wetting c U 4 , 5 1 I - • I , . 0.1 1.0 10 100 P APPLIED PRESSURE ( k•:f) 114 086A Ge tech SWELL-CONSOLIDATION TEST RESULTS FIGURE 5 Tti-PAWLAK GEOTECHNICs„ HYDROMETER ANALYSIS T FFAdN8S I U.S.STANDARD SERIES SIEVE AMAY$>$I OMAR SQUARE OPENINGS - PMR k.J 151.11N 60M-14 1914119 411 I MIN. #200 #100 #90 030 ■16 r$ Ia 3' W4. 1 1' 5 #6' g 0 _ _- 100 10 -- - 90 -- -I -- _ _- Bo 0 30 III ___ _ I — —- 70 Z -- TI1' - - Z I 411 - — -- �1 = —=._ 60 f� CC 50 —_— 1- - —- 50 W 50 — -- W - - _ _ =I - __ 4a eo _ =I= - 20 —_ -I- _— _ 90 ---- 10 100 — - =1= =_- 0 0111 .002 -003 .009 019 A37 674 :150 300 .800 118 26 4.75 t.5 124 190 919 762 p57152 2.03 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT `"'4 GRAVEL cowls I- '•'I-OIL" CLIA $. FINE I CGARSE Gravel 43 % Sand 48 % Silt and Clay 9 % Liquid Limit % Plastic,ty Index NP % Sample of Silty Sand and Gravel From:Boring 2 at 5 Feet I HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS Le. .STANDARD SERIES SIEVE CLEAN SUUAHt O• N N 2411R. 7 RR 43 MIN. 15141N. 601119. 19MIN 4 MM 1 MIN. 1100 #50 OW r 16 Ia #4 319' 304' 1 17 3' 5'6' 0100 10 - -I - -- 90 20 BO u.13U -- — — — 70 0Z _ -I Z et ba I- CC -- 20 CI. 90 100 — -I— —- — 0 41 .002 !!'., .009 .019 .037 ,974 -4110 -300 KO 116 9,36 4.79 96125 190 17.3 R7 I--14 220 DIAMETER OF PARTICLES IN MILLIMETERS �F SANG GRAVEL CLAY TO SILT meas FINE I MEDIUM COARSE FINE I COARSE Grave' 35 Sand 39 % Silt and Clay 26 % Llqu d Limi % Plastic;ty index °lo Sample of:Sil,y Sand and Gravel From: Boring 2 at 20 Feet H 114 086A i'tech GRADATION TEST RESULTS FIGURE. 6 I PW ORTH-PAWLAK Ir HYDROMETER ANALYSIS I U.S.STANDARD SERIES SIEVE ANALYSIS TIME READINGS I CLEAR SQUARE OPENINGS 0LHR 7 H 45 MIN. IS MW. 00MIN 19MJN. 4 MIN 1 MIN, M200 0100 M50 090 f16 #0 #4 M' 1j4• Mit 96 $'13' $• ----- - -- 100 Z — _I= Z a,J _= — I- 50 -1 - 50 CC1I<3- LLI L} f —- W 00 --- W IL - - 40 0- _I_ — 30 90 � — _- ,� _ PO-_ 9010- 100 — — =1- - - 0 .001 .002 .005 009 019 097 471 .150 K0 .000 1.10 2,70 4,]S .5 I 5 t90 27.1. 7(2 127P53 502 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT SAND GRAVEL :GB9LES FM I MEDNM I GOARSE FINE I COARSE Gravel 21 % Sand 45 % Silt and Clay 3,) % Liquid Limit % Plastic ty Index % Sample of:Silty Sand with Gravel From: Boring 3 at 14 Feel H 114 086A G. tech GRADATION TEST RESULTS FIGURE 7 EPWORT'H-PAWLAN GE:oTECI rNICAL • 112 5.111i..- "7=1fepr 2 Maximum Backsf=pe '2'-4'Boulcp.r .1H--1.1:__ 1 (TYP) '11=111H =fTf-Ii 11I I=1 . , I Ir J' l 'N• FiilYr f abrc (Mira' 140N or Equ } -- / / (TYP) r 44/00...., 1] H 9'(max) 1 Drain{(rep) / / \\- ,L .........."JIL N ��� ,F .__,,,,moi I I#1 I I1 I 4'Diameter PerforatedaDrain j-o 2/3 H(min) Pipe Sloped to I {H q.He ghl in Fer: Grayly Outlet (TYP) 1 112 (min.embedment) .- NOT TO ..CALL' H 4 086AFch TYPICAL BOULDER WALL DETAIL Figure 8 firpw aTP+PAW#JAK GEOTECHNICAL y w Q cs NI. cc >. c c U C] C7 C7 C7 C7 0 0 x CO cd o U 44 d c = = v' ;