HomeMy WebLinkAboutB14-0131 Geotech report . ..
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PRELIMINARY SUBSOIL STUDY
FOR FOUNDATION DESIGN
PROPOSED RESIDENCES
LOTS 1,2 AND 3, ELK MEADOWS SUBDIVISION
BUFFEHR CREEK ROAD
VAIL,COLORA.DO
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
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TABLE OF CONTENTS
PURPOSE AND SCOPE OF STUDY..........................................................................- 1 -
� PROPOSED CONSTRUCTiON................................................................................... � -
SITECONDITIONS....................................................................................................-2
FIELDEXPLORATTON.............................................................................................. 2-
SUBSURFACE CONDITIONS...................................................................................-3 -
FOUNDATI�N BEARING CONDITIONS...................................................:.............-4-
DESIGN RECOMMENDATIONS...............................................................................-4-
FOUNDATIONS......................................................................................................-4-
FQUNDATION AND RETAINING WALLS...........................................................-5 -
FLOORSLABS ......................................................................................................: 7-
� UNDERDRAIN SYSTEM.......................................................................................-7-
SITEGRADING......................................................................................................- 8 -
SURFACEDRAINAGE...........................................................................................-9
PAVEMENTSECTION........................................................................................: 10-
LIIvIITATIONS..........................................................................................................- I 1 -
FTGURE I -LOCATIONS QF EXPLORATORY BORINGS
FIGURE 2- LOGS OF EXPLORATORY BQRINGS
FIGURE 3 -LEGEND AND NOTES
FIGURES 4 and 5 - SWELL-CONSOLIDATION TEST RESULTS
FIGURES b and 7- GRA,DATION TEST RESULTS �
FIGURES 8 - TY�'ICAL B�ULDER WALL DETAIL
TABLE 1- SUMMARY OF LABOR.ATORY TEST RESULTS �
Job No. 114 d86A ��h
PURPOSE AND SCOPE OF STUDY
This report presents the results of a preIiminary subsoil study for proposed residences to
be loca.ted on L�ts 1, 2 and 3,E1k 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 bor�ings was conducted to obtain
information on the subsurface conditions. Samples af the subsoils obtained during the
field exploration were tested in the laboratory to determine theiz classification,
compressibility or swell and other engineering characteristics. The results of the field
� exploration and laboratory test�ing were analyzed to develop recommendatians for
foundation types, depths and allowable pressures far the proposed building foundation.
This report summarizes the data obtained during this study and presents our conclusions,
design recommendatzons and other geoteehnical engineering considerations based on the
proposed construction and the subsurface conditions encountered.
PROPOSED CQNSTRUCTIDN
A singte 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 Iower 1eve1 retaining cut of
the hillside slopes. Ground floors wiI�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 Ioadings,typical of the proposed type of construction. There
will be an access drive from Buffehr Creek Road to the residences. As part of the sifie
grading there xnay be boulder walls retaining cut and fi11 up to 6 to 8 feet high.
Iob No. I 14 08GA �t��
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When building location, grading and foundation loading information have been
developed,we should be notified to r�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 Yhe
time of our field exploration. There is an existing residence on Lot 4 with an address of
Ib30 Buffehr Creek Road. The tezrain consists of a narrow valleybottom with
moderately steep side slopes. Lot 1 is located on the south valley side where the terrain .
slopes down to the north,and Lats 2 and 3 are located on the n,orth valley side where the
, terrain slopes dovvn to the south. Slope grades range from about 25 to 35%on the valley
side slopes and about 6 to S%in the valley bottom. Elevation difference across each
ass�uned 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 EXPLORAT�ON
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 witli tl�e 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 tlxe tructc-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 subsails were taken with 1'!8 inch and 2 inch I.D. spoon samplers. The
samplers were drzven into the subsoils at varions depths with blows fronn a 140 pound
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hammer falling 30 inches. This test is similar to ttze standard penetration test described
by ASTM Methad 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 testi�g. � '
SUBSURFACE CONDITIONS
Graphic logs of the subsurface conditions encountered at fihe 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 bouIders that extended
down to the maYimum depth drilled of 26 feet. The approximately 3 feet deep topsoil
layer had been removed at the Borings 2 and 3 Iacations 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 encoun.tered in Boring 3 in the deposit. The sand and gravel soils
occasionally contained some sandy silt and clay zones or layers.
Laboxatory 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 condi#ions of loading
an.d wetting with a nil to Iow hydro-compression potential. Some of the more granular
soil samples may have been partly disturbed due to the rock content. Results of gradation
anatyses performed on small diameter drive samples(minus 1%a inch fraction)of the
nafizrat granular subsoils are shown on Figures 6 and 7. The laboratory testing is
summarized in Table 1.
Job No. 1 l4 086A G�t�Ch
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No free watex was encountered in the borings at the time of drilling or when checked 6
days later and the subsoils were slightly moist to moist.
F4UNDATION 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 cozrzpressible 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 zs 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 lower zisk
foundation.
DESIGN RECOMMENDATIUNS
. FOUNDATIONS
Considering the subsurface conditions encountered in the exp�oratory 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 far a spread
footing foundation system.
1) Footings placed on the undisturbed natura�soils should be designed for an
ailowable bearing pressure of 1,500 psf. Based on experience,we expect
settlement of footings designed and constructed as discussed in this section
will be about 1 ta 1%z inches for the assumed light ioadings. 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 loadings. We should review
Job No. !14 OS6A Gec�t@Ch
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the settlement patential when foundation loadings are available and make
recommendations to mitigate the settlenr�ent if needed.
2) The footings should have a minimum width of 18 inches for continuous
walls and 2 feet for isolated pads.
3) Exteriar footings and footings beneath unheated areas should be provided
with adequate soil cover above their bearing elevation for frost protection.
Placennent of£oundations at least 48 inches below exterior grade is
typica.11y used in this area,.
4) Con#inuous foundatiorz waIIs should be weIl reinforced top and bottom to
span Iocal anomalies and better withstand the effects of som.e differential
settlement such as by assuming an unsupported length of at Ieast 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 leval extended down to the firm natural soils. If the
footings are designed to bear entirely on the sand an�d gravel sails all silty
clay soils shouid 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 footing areas should be dewatered
before concrete placement.
6) A representative of the geotechnical engineer should observe a11 footing
excavations prior to concrete placement to evaluate bearing conditions.
FOUNDATION AND RETAINING WALLS
Foundation walls and retaining structures which are laterally supported and can be
expected ta undergo oniy 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 backfiil consisting of the an-site soils. Cantilevered retaining structures which are
separate from the main buildings and can be expected to deflect sufficiently to rnobilize
Job No. l i4 086A �P��
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the full active earth pressure condition should be designed for a Iateral earth pressure
computed on the basis of an equivalent fluid unit weight of at least 45 pcf for backfill
consisring of the on-site soils. The backfill should nofi contain topsoil or oversized rocks.
. All foundation and reta�ining 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 canditions behind the
wa11s and a horizontal backfill surface. The buildup af 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 ta prevent hydrostatic pressure
buildup behind walls.
Backfill should be placed in uniform lifts and compacted to at least 90%of the maxiinum
standard Proctor density(SPD}at a rnoisture content near optimum. Backfill in pavement
and walkway areas should be compacted to at least 95% SPD. Care shauld be taken not
to overcompact the backfill or use large equipznent near the wall, since this could cause
excessive lateral pressure on the wall, Same settlement of deep foundatian wall backfill
shoul�.be expected, even if the material is placed correctly, and could result in distress to
facilities consfructed on the backfill. Use of a select granular import material such as
raad base and increasing compactiott to at least 98% SPD could be dane to reduce the .
settlement poten#iai.
The lateral resistance of foundation or retaining wall foatings will be a combination of the
sliding resistancc of the footii�g 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 af friction of 0.40. Passive pressure of compacted
backfill against the sides of the footings can be calculated using an equivalent fiuid unit
weight of 375 pcf. The coe�cient of friction and passive pressure values recommended
above assume ultimate soil strength. Suitable factoxs of safety shauld be included in the
design to limit the strain vtrhich will occnr at the ultimate strength,particnlarly in the case
of passive resistance. FiII p�aced against the sides of the footings to reszst lateral Ioads
Job No. 114 086A ��h
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should be a suitable ganular material compacted to at least 95%of the maximum
standard Proctor density at a moistnre content near optimum.
FLOORSLABS
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 sail rypes at subgrade. To reduce the effects of soxne differential
movement, floor slabs should be separated from aZl bearing wa11s 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 experzence
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 cansist of
minus 2 inch aggregate with at teast 50%retained on the No.�sieve and less than 2%
passing the No. 2Q0 sieve.
All fill materials for support of floor slabs should be coxnpacted to at least 95%of
ma�cimum standard Proctor density at a moisture content near optunum. Required fill can
consist of the on-site granular soils devoid of topsoil and oversized rocks, or a suitable
granular nnaterial such as road base can be imported.
UNDERDRAIN SYSTEM
Although free water was not encountered during our exploration,it has been our
experience in mountainous areas and where c2ay soils are present that Ioca1 perched
groundwater caxi develop during times of heavy precipitation or seasanal runoff. Frozen
ground during spring runoff can also create a perched condition. We recommend below-
graae construction, such as retaining walls, crawlspace and basement areas,be protected
from wetting and hydrostatic pressure buildup by an underda-ain system. .
Job No. I 14 086A HPtLCh
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The drains should consist of draznpipe placed in the bottom of the wail backfilI
surrounded above the invert Ievel with free-draining granular material. The drain should
be placed at each level of excavation and at least 1 foot below lowest adjacent finish
grade and sloped at a minimum 1%to a suitable gravity autlet or sump and pump. Free-
draining grazaulaz material used in the underdrain system should contain less than 2%
passing the No.20p 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 1%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 axe located as p�anned and cut and�11 depths are limited. We assume the cut
depths for the basement level will not exceed one level, about 10 feet. Ernbanlcment fills
should be limited to about 8 ta 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 shauld be ca,�efiilly prepared by rexnoving aIl vegetation and
topsoil a.nd 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 wails 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
Iimited to 8 fcet in height. Tlie baulders for the walls should have an ernbedment depth
into the subgrade a#least 11/a feet. The boulder wall subgrade should be compacted to the
placement of the boulders. A subdrain should be provided behind tYze walls. The walls
should be battered back at%z Horizontal to 1 Vertical or flattex. Backfill of the boulder
walls can consist of the on-site predominantly granular soils and should be compacted to
at least 45% SPD neat optimum moisture content.
Job No. t 14 086A Ge�t�Ch
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Permanent unretained cut and fill slopes should be graded at 2 horizontal to 1 veztical or
flatter and protected against erosion by revegetation 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 detenmine if the seepage will adversely affect the cut stability. We shauld
review the site grading pians prior to construction.
SURFACE DR.AINAGE
1'ositive 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:
1) Inundation of the foundation excavatzons and underslab areas should be
avoided during consh�tction.
2) Exterior backfill should be adjusted to near optirnum moisture and
compacted to at least 95%of the maximum standard Proctor density in
pavement and slab areas and to at least 90°fo of the m�imum 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 aIl directions. We
reconnmend a minimum slope of 12 inches in the first l.0 feet in unpaved
areas and a minimum slope of 3 inches in the first 1 a feet in paved areas.
Free-draining wall backfiil should be capped with filter fabric such as
Mirafi 140N and about 2 feet of the ou-szte�uer graded suils to reduce
surface water inf Itration.
4) Roof downspouts and drains should discharge well beyond the limits of aI1
backfill.
5) Landscaping which requires regular heavy imgation should be�ocated at
least S feet from foundation wa11s.
Job No. I(4 086A C�Pt@Ch
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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 fue truck turrz-around area. Traffic
loadings for the drive have not been pzovided but are expected to be light and typical of
the proposed development. We assume a traffic loading 18 kip equivalent daily load
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 whzch is cansidered a relatively
poor support for pavement sections. We estimate a Hveem stabiloxneter"R"value of
about 8 far the subgrade soils. The soils are rnoc3erately susceptible to frost heave.
� Based on our experience, an 18 kip EDLA af 15,a Regional Factor of 2.25 and a
serviceability index of 2.0,we recomznend the minimum pavern�nt sec�ion 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, appraved by the engineer and placed and
compacted to the project specifications. The base course should meet CDOT Class 6
specifications. All base course and required subgrade filI should be compacted to at least
95%of the maximum standard Proctor density at a moisture content within 2%af
optimum. Concrete should have a minimum 28 da.y 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, scarif ed to a depth of 8 inches, adjusted�to near
optimum moist�ure and coinpacted to at least 95%of standard Practor density. In soft or
wet areas,the subgrade may require drying ar stabilization prior to fil1 placeinent. A
geogrid and/or 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 086A �t�
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shoutd be corrected before placing pavement materia.ls. The subgrade improvements and
placement and compaction of base and asphalt nrzaterials should be monitored on a regular
basis by a representative of the geotachnical engineer.
If Grass Pave 2 is used for the fire truck turn—around area at the end of the drive,we
recommend a miniznum 12 inches of CDQT Class 6 or Class 2 base course be provided
below the material. The subgrade should be stabiiized if needed,as discussed above,
prior to placing the base course.
Once traffic loadings are better laaown, 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 wananty either
express ar implied. The conclusions and recommendations subrnitted in this report are
based upon the data obtained from the explora#ory borings dr[lled at the locations
indicated on Figure 1, the proposed rype of construction and our experience in the area.
Our services do not include detezrnining 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#his special field of practice should be
consulted. Our findings include interpolation and extrapolation of the subsurface
conditions identified at fhe exploratory borings and variations in the subsurface
condi�ions may not become evident until excavation is performed. If conditions
encountered during construction appear different from those descrzbed in this report,we
should be notified so that re-evaluation of the recommendations may be made.
This report has been pregared for the exclusive use by our client for design pu�poses. We
are not respansible for technical interpretations hy others of our informatian. As the
praject evolves, we should provide eontinued consultation and fie2d services during
7ob No. I I4 086A
C�t@C�'l
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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 G (l���CAL, INC. �
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David A. Young, P.E. � 216 �
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Reviewed by: ��� a��
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Steven L. Pawlak, P.E.
DAY/ksw
cc: Elk Meadows Development—Brian Redinger(t�rian�usolarisvaiLcc>m)
1ob No. i 14 086A �t�n
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114 086A (,�..'�7"�`,,°�`.h LOCATIONS OF EXPLORAT4RY BORINGS Figure 1
H�PworrrH-Pnwvuc G�orecx[ucw�
BORING 1 BORING 2 BORING 3
LOT 1 LOT 2 LOT 3
ELEV.=8320' ELEV.= 83i6' ELEV.= 8312'
8320 8320
4/i 2
8315 �2/�2 8315
WC=17,1
DD=106
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&314 30/t2 WC-5.2 8310
WC=8.fi +4=43
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p�� o� 13/12 0•. -200=51
83Q5 ,o'° 32/12 WC=4.9 8305
a�i WC=8.0 :Q; -20Q=29 �
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p.: 59/12 0° 18l12 a� -200=35
$295 wc=3.s a: 8295
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8290 s29a
8285 8285
Notes: ij Explanation of symbols is shown on Figure 3.
2)Topsoil layer about 3 feet#hick removed at
Borings 2 and 3 prior to drilling of borings.
H
�14 086A �h LQGS OF EXPLORAT�RY BORINGS Figure 2
HEPWORTii-PAWLAK Gk*OTECEiNICAL
LEGEND:
� 'fOPS01L;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); siliy, sandy to very sandy, medium stiff to stiff, moist, brown, low plasticity.
� SAND AND GRAVEL(SC-GC};with cobbles, possible boulders,silty to very siiry, occasionally ciayey, some sandy
silt and clay zones, medium dense, slightly rrtoist to moist, mixed brown, low piastic fines, rocks are primarily
subangular.
� Relatively undisturbed drive sampie;2-inch I.D. California finer sample.
� Drive sample; standard penetration test(SP�, 1 3/8 inch I.D.split spoon sample,ASTM D-1586.
4/i2 Drive sample blow count;indicates that 4 blows of a 140 pound hammer falfing 30 inches were
required to drive the California or SPT sampler 12 inches.
� Practical drifling refusal.
---� Depth at which boring had caved when measured 6 days after drilling.
NOTES:
1. Exploratory borings were drilled on April 10,20�i 4 wi#h 4-inch diameter continuous flight power auger.
2. Locations of exploratory borings were measured approximatefy by pacing from features shown on the site 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 tapsoil.
4. 7he exploratory boring locations and elevations should be considered accurata only to the degree implied by the
method used.
5. The lines between materials shown an 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 c�ecked 6 days later. Fluctuation in
water level may occur with time.
7. Laboratory Testing Results:
WC =Water Content(°�}
DD = Dry Density{pc�
+4 = Percent retained on the No.4 sieve
-200 = Percent passing No.200 sieve
LL= Liquid Limit(°!o}
PI = Plasticity Index(°k)
NP= Non-Plastic
114 086A r�Q��� LEGEND AND NOTES Figure 3
HePwoRrtrPaw�,qK Geo7ECKN�cqL
Moisture Content = 17.1 percent
Dry Density = 1 Q6 pcf
, , Sample of:Sandy Silty Clay
I ; � From: Boring 1 at 5 Feet
0 !
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� ,
1 '
i � , I i i '
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o � � � �
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v�i � � , � ; upon � !
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0•1 1.0 10 100
APPLtED PRESSURE(ksf)
� � Moisture Content = 8.6 percent
� j Dry Density = 117 pcf
' ; Sample of:Silty Clayey Sand with Gravel
' � �' i '� i From: Boring 1 at 10 Feet
0 � ' i � � i I
'. ' , i i i � � ' � � � i
I i � � � i ,
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o i Compression
� � ' ' � upon � ,
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a , , �
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U 4 � : ! � '
� � , � � � � , � � � i �
5
0.1 1.0 10 100
APPLIED PRESSURE (ksf)
H
114 086A �,-��tE?��'"'� SWELL-CONSOLIDATION TEST RESU�TS FIGURE 4
HEif'WOR7'H-F'AWIAK GEL>TECHNICAL.
i
i
' Moisture Content= 8.0 percent
' ' ' ' ! ' Dry Density = 121 pcf
; � Sample of:Silty Clayey Sand with Gravel
; ' From: Boring 1 at 15 Feet
0 � � �
� ; �
� ; ;
, ,
, ; � �
1 � � �� � � � � � �
o I , � I ' i � ! I
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�
�n � � , upon
�
aWC 3 � ; � , ; wetting
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O � � � � � � ! � � I I I � � '
4 � � . i ��
, i � ! I I � I � ( ;I ' i i
5 � � � � , I ; � � �
I
, I � �
i i i , I , � � I i � , ,
, , .
, � i � �
0.1 1.0 10 100
APPLIED PRESSURE (ksf)
� , , Moisture Content= 16.5 percent
, ;
� ' ' �� � � Dry Density = 108 pcf
' ; ', , Sample of:Very Sandy Silty Clay
� � � � � � ' ; From: Boring 3 at 4 Feet
�
0 ' i ! �
� �
� ; j
! �� � , � �� � � � I � � �
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oi' I � ± I� � j ; '
Z 2 ' i I , ! , !
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� �
� P ! I
cn ; ; � ' uon
� 3 � � � � I i , � � � � � I � wet#ing �� j �� '
� ' � ; �
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i '
j '� �
i �
5 , '
��� �, ` �
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0.1 1.0 10 100
APPLIED PRESSURE (ksf)
114 086A ��PteC�''� SWELL-CONSOLIDATION TEST RESULTS FIGURE 5
r{Gt'WORTH-PAWl.AK GF_(:)TECfiP�ICAi..
� HYOROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S.STANDARD SEPIES CLEAR SOUARE OPENINCaS
24 HH. 7 HR
<SMIN. 7SMIN 60MIN.�9tA1N aMIN. 1fA1N 5200 a100 1150 C30 /!16 #B lA 3/8' 3!d' 11/p' 3" 5' 6' B'
0 10U
-. .._ � _ _ �.. __ . �__._�.:�. _ .� _�
�� 90
- ._. _. - --- _ . ._ _ ._ . .
20 - -- � . I . . � 80
-_ f.:
0 30 -__. . : _.. _ . _ . .__. _....
W _._ . . . �� (�
Z �. .._ -. . --,... . _� _ .__...-. � . . . -�..- _ .. Z
FQ� �- � _ ____. -. _ � _... �.�_. .._ B� �
� � _. _ -- : - - i _:_. - a
F �� --- . . . . .. _. . . _ _ 5a �.
Z . . . .. ._ . . -- -_ . .._ ..:... - - ._. ._ ---_. -. _ . Z
_ ... - --- - _- _ .._
i1I � -. __... ----. _� �_.- .. . . _ .___._ _ ... . UJ
(� ._ . ._ .. .. _. . 40 (.�
� - .._ _ . _._ _-.� '__-. . . ._ . .� ..-__. � -..:_ . �
W70 _ . _ . . _._ . ._._ __' ___. ::.._ .____ _. . -- - uJ
�.. . ._ . .._ .... _ . ._--_.. ..._..-- _ .. .. . __..._._.. . -_.._ _._. . 30 d
--
. . . . _ .... ._ . . .- � -- � - � --- .. _. _ _ .
� - - - �- � - - --
_._. . . .___. _ ._ -_�... . _ ._ __. .
80 � - ... -- --- -� --. ._. _�_- �. . _-. .
. . . - - . _.. . ._ -- � 20
� _ .... _. __ . . .___ ._ _ . . .. _ . __ . .
--
. . .._ - -- � -�-- --`--� -- �
. ._. _ _'-�--.. _. ." . ..._. '�---
gp ��- �-- -------��---- ._._ ' __ . .—.____.
_-
.._. _._ ... .__ . .__.. 70
. -_. . ._ _. . __ ... . . _ ____ _ ..__'_-'. .. ___ _. . ._ ._—_ _____ _._.
._. . ._. _._ ._. _ ._.__. __ ._ .._.__. . ._ _._._ . .--�___
100 .. .___'— _. _ ..__.. . _..
0
001 Op2 .005 .009 019 .037 .070 15D 300 6p0 1.iB 2.36 A.75 9.5 12.5 19.0 37.5 762 127t52 �
DIAMETER OF PARTICLES IN MILLIMETERS
SHND GRAVEL
CIAY TO SILT coee�S
FINE MEDIUM COANSE FINE COARSE
Gravel 43 % Sand 48 % Silt and Clay 9 °/a
Liquid Limit % Plasticity Index NP %
Sample of:Silty Sand and Gravel From:Boring 2 at 5 Feet
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READ{NiaS U.S.STANDARD SERIES CLEAR SUUARt UPENIN(iS
24 HR. 7 MR
aSMIN. iSMIN. 60MIF1.19NP1. 4MM iMIN. C200 p70D d50 �Y�q !16 YB V4 3/8' 3.`d� t tfl' 3' 5 6' 9-
� ' . . ..'_'__ _. ._.'_ '._. .___.. __ . ._ .. __._.__..__. ._'_"_____. . .._' _ . _'_ _._.__ 100
.. . .._- �--- _ _--_. _ --- .... .-- -- - --- � --._
_. -- - --- � -� -- -.. .._. .-._-- .__ -- -- --._. ._ .
70 90
_ . . .. -- . _ _ . . . _ . . .--- . . .
20 _ _. . . _- -- - — -� � -- �
-- -. .. .- --- .. __. -' _. .._� -- --�- - -_ _
_.. _ .. __._. _. . . . _ .. . ... _ .._
- --- -- -- -- .. _._ ...._ .. -- -_. -.._ - -__ ...._..
W � - . . . 70 (�
_.. _... .._._._ .. _. _ . ._ .._ _ __ ._ _ _- .. ---- --
. . _.. . ... _._. _...' ---- .'---- . . . .- � --� ---
Z - - . .. _._ .. _ ._ �_ �. . .-_ ._ - �----�- - - � � -- .. - Z
---- - -_. _....._ _ .._.��. ..---_ . _
Q40 � -- . ._.— _. _.. - .- _—_. :..__. (A
F- __ _. _ _--- - - - - - . -- - _._ � (n
W - - - -- _ _ _ -— - a
_ _ _ _ -_ - - -- _
o� So _ _ �
__- - -- - - - -
z _ - _ _ .__ __ � ..- ._ - z
_
� � _ _ -- ,o �
_ _ _
- -- - -.
� - — _ __: - -- - _. o�
_ - - _ _ - - -
w ,a w
a — _ _ ---__ _ - - - so a
— __ - - - -
_ _ _- - -_ _ __�_
-- - — -
so -- - - - o
- - -- -- - 2
-- _ _ _. __ _
_ — --- .. _ _ _ _ - --
-- _ _-- - ----— _
90 .._._ ___._.
.. . ..____. 10
.._ . . .. _ . . .—� --�-- . _._- .__-_.-_ _ . . -—-_- .
_ __ .. . __._ �_ . _. ...—. ..._.-- -- -� ----'-_.
100 0
.00t .002 .pp$ 069 .079 .037 A7a .150 300 .600 1.18 2J6 4.75 9.5 12.5 '90 375 Ifi2 r27152 20.3
DIAMETER OF PARTICLES IN MILLIMETERS
sario �ar+v�
CLAY TO SIIT COHB�FS
FINE MEDIUM COMSE flNE COAHSE
Gravel 35 % Sand 39 % Siit and Ciay 26 %
Liquid Limit �o Plasticity Index %
Sampte of:Silty Sand and Gravel From:Boring 2 at 20 Feet
114 086A ��P"t�� GRADATION TEST RESULTS FIGURE 6
HF'FWOR'iH-PAWI,AK GE'OTECiiNIGAI.
�
HYDROMETER ANALYSIS SIEVE APIALYSIS
TIME READINGS U.S.STANDAflD SERIES CLEAR SQUARE OPENINGS
24 HF ]HR
aSMIN. iSMIN. 60hi1N.19MIN. 41RW 11AIN. C200 d100 d50 A30 /f18 N8 94 3f8' J!a' �72' J' S'6" B'
0 ��
-_ _- � __ . . .._. __ _.. . . :__ .: . ... ___.
- ._._ �. �... _ .�.. ....._ �. ..___ . . ___ _ '. ._..
. _ _ ____ . ___.__'_.. ___ .. __.__ _- _�._-: _ . . _ _.._� . . _..
- . __ _ ._.._ _ .. .. .- . _. .__ _.. _.. ____ ...—._ _ . .___..
_'__ .___ . ._ .. ___. _ _. _._ ._ ___ ._..__._ -.__.._... . .____... '__. . ..__._ ._. _
10 �
. .._ _. . .__ -_.._ . _ . ._ _. _ _
. .. ..._ . ... ..._ __ . -.__ _ _ . _ __ _ _... .. _.
�.:. . � ._ � ._ _ ._ . . �-:._ —_ . ..__'- _ .__ .._.
_ .. .__ . .—. . _ __. ._ .-. .._ _._._ . . . ._.. __ -._.- ___
_.. _.... __ . . __.. -_ .. - . ._. _ .___—__ . . ._ _._. ___ _'.
20 �
---
- -- .. . . . . .. _. .._.._ _. _ _ . _ -- - � --- ---
_. _. -_ . __. _._ - . -- . . ..._ -- -
_ - -- _ . -__ _ _ I _ _ -
_ __ -_ _- -_ __
_ __ _ �- - - =-
__ _ - - - --- - -
__ -- - __ ._ - --
30 _ ._ _ _ . 70
_.. . _.. _ . . .._ __._ ._._. __. __ . _._ .. .. _ . __ _
_.._ __. __. . ._-_ . ..__. . . __ _ .'-_ . - �-� .-::_.
. . . . . _ .— . . ._ _ . . _ . . _ ..__ __ __ __.
._-.. _... .._-. _._ _.. . . _.. _..__ '_. �_:.- '__. -_ . .__
_ __ _.. .... __ ____ _ _
. . . . _._. . . .__.. _. __ ._ ___ . _ -_._ _.. __ ' ___ _-
" _ _ ___ _._ __. _ .___ __._ __ . �_ _' .
40 �
W -._. . . - . - .. -- -- ._.. .- -- - ' ... 60
. - -- - -- --� - - '-- -- --- � ---. _. _. _._-— - -�-'---� --- - -
_._
- ..
---- - . -.. .. ._ . _._ __._._ .._. . _ ..__.._ . . Z
__
_.. .._. _ ...._ .._ .. _. . ..
I-a. - - -- _- __ - _ ' - - -- �
LL1 -- - - �- - .. ....-- ..... ..__ � _ . .
--� - � --- --- ' Q
� - - � - �- -� -�-. — ----- �� -- - - - -
- -.. _. _ __. -- � -
so _ _- -_. ... _ - ----- --- - a
F- .- - . ._ ... . ---- _.,._._ _.. _. 50 �
Z ._ _ ...__ . _..__ _. _ :— . _ . .— - - - --
__ .____ ..__. __ - -- . _-- --__ � . . :
-- Z
W __ - - - �._ _: _ : _. U
U -- -
� -- - - — - _ _.
W 60 -- - : -_ :. _ - - _ - . __ - --- - �
' � :._ W
a __. __ _ _. . __ ao a
._ __ - - -
_ -- _ _ - -
_ _ — -- -- -- - -- _
__ -
_ _ -- . _ _ . —--
__ .. _--— - - --.. _ . _ --
_. _ - -- -- ---
�o - - -- - --.. _ _ _---—-- — - - -
-- -- .._-. �- - --- .... 30
__ _..
--- ... ___ ._ _. ._. .___- -�-- -_.. .
. - _._. . _.._ _'_ --.
._ ..-. " -- -- _ _..
. . . _.. ._ . _— .�-- --'. "- - � - - � - -- --
- .. :.- ... ---� � —- —.. . -
...- - -- -.. ._._ (- ._ - . ..-- _
. __ � - ---. . .--- - ... _
- __ . -. -� ---- - - � - -'----- -I ��� ..._ . -. -,.:-
� .. .. . � �.�_ .._- _— ..— --- - -.. .-.._ _--------- ..__._.__..
. . ' -- ..._— �---�
.. ---- --.. .-
._. _--- __. .
__.. - -- --. . ._ __.- .___.. . ___. 20
_ . . . __ . -- -_ ._._ ._.- �--- --- -- - ��- -
_.._ .__ . ._ ..... �
-... --. . .--.. ... . __ _,_ �-
. _ . _ _ . ___.. .. - .
- - '-
-._ ._. _.. ._ -.. . _- - . . ._. - - ��
. __.. '- -._ --- �_ - -�.
___ .._. -_ � . — - -- . . --
-- -._.. .- -- - -- -� ..
9D _. _ _-- -— . __- - �-
� _ . . _ .._ -.- ..- ." . 10
_. ._.. .. .. . _.
. .. . . . _-- ' -- - ---
_
._ _ _ --- - . � - . ._- _.. .-- --- . .. _-' � . :__ �. ._.._ ..
. . _ . ... . _ .. .--- . __--- ....--- -� -- . _ _.._..
100 - -- -- �- --� - -� --- - .._._ _... - . .
O
.007 .002 005 .009 .Ot9 .0'J7 074 .150 .JUO .5pp 7.78 2.36 4.75 9.5 12.5 1D.0 3].5 76.2 147�� �
DIAMETER OF PARTICLES IN MILLIMETERS
CLAY TO SILT SAND GtuVEL
COBBLtS
FINE MEDIUM COARSE PIr�E COARSE
Gravel 21 % Sand 45 % Silt and Clay 35 %
Liquid Limit % Plasticity Index °�
Sample of:Silty Sand with Gravel From: Boring 3 at 14 Feet
114 086A �tGC�""1 GRADATION TEST RESULTS FIGURE 7
tiLPWOR7�k�f-PAWL1aK GEOTI=C}9N1C;At..
i
�
,.:'i�r� _
�-����i--
�����f�— I�_ 2 Maxtmum
�f���, l ` ' Backslope 2�P'Boulders
-�i����l �-
III— .
' _ I _ �
�
_ ��H� ...-
::_��� �
- , : f ti
Filter Fabric
(Mirafi 140N or Equiv,} / � ��z
�P� ` ,j -.- � �1 H=8'(max�
r �
Orain Gravel ' �
��� . � � 1 �
� �
,
�.,::: � _,;,I 1 I,;,TH I�I I l,Tl I 1�1 I ITI 1
4°Diameter
Perforated Drain 2/3 H{min.)
Pipe Sloped to (H=Height in Fcet)
Gravlry Outlet
(TYP)
1 1/2'(min.embedment)
NOT TO SCALE
,�HJ?�
114 086A (��VI.�C�'1 TYPICAL BOULD�R WAL� DETAfL Figure 8
HEPWQRTH-PAWIAK GEOTECHNICAL
. .
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