HomeMy WebLinkAbout1.04 Geology~tech HEPWORTH -PAWLAK GEOTECHNICAL Hepworth,Pawlak Geotechnical, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone, 970-945-7988 Fa" 970-945-8454 em.ail: hpgeo@hpgeorech.com
PRELIMINARY GEOTECHNICAL STUDY PROPOSED RESIDENTIAL DEVELOPMENT CEMETARY PARCELS 5-1 AND 5-2 BATTLEMENT MESA GARFIELD COUNTY, COLORADO JOB NO. 105 469 JUNE 13, 2005 PREPARED FOR: BATTLEMENT
MESA LAND AND DEVELOPMENT COMPANY ATTN: TOM BEARD P.O. BOX 6008 BATTLEMENT MESA, COLORADO 81636 Parker 303-841-7119 • Colorado Springs 719-633-5562 • Silverthorne 970-468-1989
I~·. ~_.j TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY ............................................................................ -I -PROPOSED DEVELOPMENT ..........................................
............................................ -I -SITE CONDITIONS ....................................................................................................... -2-GEOLOGIC SETTING
................................................................................................... -2 -PROJECT AREA GEOLOGY ..........................................................................
.............. -3 -FIELD EXPLORATION ................................................................................................. -4-SUBSURFACE CONDITIONS .......................................
............................................... -4-GEOLOGIC ASSESSMENT .......................................................................................... -5 -GAMMA RADIATION
.............................................................................................. -5-MOISTURE SENSITIVE SOILS ............................................................................
... -6 -MAN-PLACED FILL ................................................................................................. -6 -CONSTRUCTION RELATED SLOPE INSTABILITy ..................................
.......... -6-DEBRIS FLOWS ............................................................................................................ -7 -EARTHQUAKE CONSIDERATIONS .................................
......................................... -8 -PRELIMINARY DESIGN RECOMMENDATIONS .................................................... -8 -FOUNDATIONS .................................................
........................................................ -9 -FLOOR SLABS .......................................................................................................... -9
-UNDERDRAIN SySTEM ........................................................................................ -10-SITE GRADING ..........................................................................
............................. -10-SURFACE DRAINAGE ........................................................................................... -10 -PAVEMENTS SECTIONS ................................
....................................................... -11-LIMITATIONS .............................................................................................................
-II -REFERENCES .............................................................................................................. -13 -FIGURE I -GEOLOGY MAP AND BORING LOCATIONS FIGURES
2 -4-LOGS OF EXPLORATORY BORINGS FIGURE 5 -LEGEND AND NOTES FIGURES 6 -10 -SWELL-CONSOLIDATION TEST RESULTS TABLE 1-SUMMARY OF LABORATORY TEST RESULTS Job No.1 05 469
l ~-,~ . , PURPOSE AND SCOPE OF STUDY This repoll presents the results of a preliminary geoteclmical study for the proposed residential development to be located at the Cemetery Parcels
5-1 and 5-2, Battlement Mesa, Garfield County, Colorado. The project site is shown on Figure I. The pUipose of the study was to evaluate the geologic and subsurface conditions and their
impact on the project. The study was conducted in accordance with our proposal for geotechnical engineering services to Battlement Mesa Land and Development Company, dated March 31,2005.
A field reconnaissance and review of the exploration program by Chen and Associates (l982a and 1982b) was conducted to obtain information on the site and subsurface conditions. The results
of the field recOimaissance and the previous exploration and laboratory testing were analyzed to develop reconunendations for project plamling and preliminary design. This report summarizes
the data obtained during this study and presents our conclusions and recOlIDnendations based On the proposed development and subsurface conditions encountered. PROPOSED DEVELOPMENT The
proposed Cemetery Parcels 5-1 and 5-2 will be subdivided for multi-family units. The development plan was not available at the time of our study. The propelly boundary is shown on Figure
1. Public streets will access the building sites. We assume the residences will be typical of the area and be one and two stories with slab-on-grade, crawlspace or partial basement level.
Grading is assumed to be relatively minor with cut and fill depth less than 10 feet. The development will be serviced with municipal water and sewer systems. If development plans change
significantly from those described, we should be notified to re-evaluate the recommendations presented in this repOli.
" -2 -SITE CONDITIONS Parcels 5-1 and 5-2 are located in northern part of Section 17, T 7 S, R 95 W. The terrain is typically rolling with an overall slope down to the west-northwest
towards the Colorado River. The natural slopes on the parcels range from about 5% to 10% throughout most of the proposed development area up to about 20% to 30% adjacent to a relatively
large drainage located in the northeast part of Parcel 5-2. The elevation ranges liOIn abont 5680 feet to about 5430 feet across the entirety of Parcels 5-1 and 5-2. Vegetation throughout
the proposed development area consists mainly of native grass and weeds with scattered sage. Several small drainage charmels and irrigation ditches run through paris of the proposed
development and the main drainage charmel through the area is located in the northeast pali of Parcel 5-2. Water was observed flowing in the main drainage charmel and in the irrigation
ditches at the time of our field reconnaissance on June 9, 2005. The exposed cobbles and boulders on the parcels are subrounded to subangular and consist mainly of basalt boulders with
lesser amounts of siltstone, sandstone, and shale. One and 2 story wood frame homes ar'e typical in the existing Battlement Mesa development. GEOLOGIC SETTING The project area is located
in the west-central part of the Laramide-age Piceance Basin. The development site is located in the Lands End Formation formed during the Bull Lake Glaciation in the Late Pleistocene.
River down cutting induced terrace development in the Lands End Formation prior to deposition ofthe Grand Mesa Formation Terrace during the early pari of the Pinedale glaciation. Further
river down cutting and terrace f0I111ation occurred in the Grand Mesa fan complex during the late Pleistocene. At least two major debris flow episodes have occurred on the fan complex
to the north and south of the project site. These events are probably associated with the latter part of the Pinedale glaciation in the Late Pleistocene and Early Holocene. The formation
ofthe Grand Mesa alluvial fan complex and subsequent debris flow events were followed by Job No. 105469 ~tech
.: . " -3 -deposition of modern alluvial fans at the mouths of Battlement Creek and Monument Gulch. The fan deposits are underlain by the Eocene and Paleocene-age Wasatch Formation which
consists mainly of shales and claystones with some lenticular beds of sandstone, conglomerate, and limestone (DOImell and Others, 1986). The Wasatch Formation outcrops on the lower mountain
slopes to the southeast of the site as well as on the lower mountain slopes along the northwestern side of the Colorado River valley. The Green River Formation overlies the Wasatch Formation
and forms shallow subcrops and outcrops on the upper part of both mountain slopes. The bedrock formations are essentially flat lying throughout the area. The closest fault zones to the
project area with known or suspected movement in postglacial time, within about the last 15,000 years, are the Williams Fork Mountain fault zone located roughly 104 miles to the n0l1heast,
the southern section of the Sawatch fault zone located roughly 108 miles to the southeast, and the Roubideau Creek fault zone located about 76 miles to the south (Widmann and Others,
1998). PROJECT AREA GEOLOGY The main geologic features in the project area are shown on Figure I. Man placed fill (at) was observed at several locations within the project area. The
fill consists mainly of concrete and rebar, plastic, organic waste, and displaced native soils. The surface geology in the project area consists of debris flow deposits (Qat) with colluvium
derived from debris flow deposits (Qc) on adjacent escarpments. Debris flow deposits locally consist of pebble, cobble and boulder size rock in a grey to brown matrix of coarse clayey
sand. The debris flow deposits are poorly sorted with clasts consisting mainly of basalt boulders and lesser amounts of sandstone, marlstone, siltstone and claystone. Debris flow deposits
in the project area are overlain by silty, sandy, alluvial clays ranging from 6 inches to about 15 feet in depth at the boring locations (Chen and Associates, 1982a and 1982b). Job No.
105469
.: " -4 -Drainage bottoms adjacent to the project area are underlain by relatively shallow stream channel alluvium (Qal). The alluvium consists mainly of silt, sand and gravel (Donnell
and Others, 1986). FIELD EXPLORATION The subsurface conditions were evaluated by Chen and Associates (I 982a and 1982b). Twenty-one exploratory borings were drilled at the approximate
locations shown on Figure 1. The borings were advanced with 4 inch diameter continuous flight power auger. About the western 500 feet of the current Parcel 5-1 boundaries was not included
in the Chen and Associates (I 982a) study and does not contain borings. Samples of the subsoils were taken with I 'Is inch and 2 inch LD. spoon samplers. The samplers were driven into
the subsoils at various depths with blows from a 140 pound 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 ofthe subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the
Logs of Exploratory Borings, Figures 2, 3 and 4. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered in the borings are shown on Figures 2, 3 and 4. The subsoils,
typically below a shallow topsoil layer, consist of nil to 15 feet of stiff to very stiff sandy silty clay overlying relatively dense, sandy gravel, cobbles and boulders in a clayey
matrix. Drilling in the dense gravel with auger equipment was difficult due to the cobbles and boulders and dtilling renlsal was encountered in the deposit. Job No. 105469
. : '. ) -5 -Laboratory testing performed on samples obtained from the borings included natural moisture content and density, liquid and plastic limits and finer than sand size gradation
analyses. Results of swell -consolidation testing performed on relatively undisturbed drive samples of the clay soil s, presented on Figures 6 through 10, indicate low compressibility
under natural low moisture and light loading conditions. The samples typically showed low to moderate collapse potential (settlement under constant load) when wetted and moderate to
high compressibility under additional loading after wetting. The laboratory test results are summarized in Table I. No free water was encountered in the borings at the time of drilling
and the subsoils were slightly moist to moist. GEOLOGIC ASSESSMENT Geologic conditions that would make the proposed development infeasible were not identified in the probable building
areas. Conditions of a geologic nature that should be considered in project planning and design are gamma radiation, moisture sensitive soils, man-placed fill, slope instability, debris
flows and the potential for strong earthquake related ground shaking. GAMMA RADIATION The proposed development area is not located on geologic deposits that would be expected to have
high concentration of radioactive minerals. However, there is a potential that radon gas could be present in the area. It is difficult to assess future radon gas concentrations in bui
ldings before the buildings are constructed. Testing for radon gas levels could be done when the residences and other occupied structures have been completed. New buildings are often
designed with provisions for ventilation of lower enclosed areas should post construction testing show unacceptable radon gas concentration. Job No. 105 469 ~tech
.: -6 -MOISTURE SENSITIVE SOILS Results from laboratory testing of samples taken at the site for previous studies (Chen and Associates, 1982a and 1982b) indicate that the silty clays
overlying debris flow deposits in some parts of the project area may be hydrocompressive. Hydrocompressive soils, when dry, provide acceptable foundation support. Post construction wetting
of hydrocompressive soils can result in relatively large differential settlement. Site specific subsoil studies will be needed to evaluate the hydrocompressive potential of the foundation
soils and to develop appropriate foundation designs. Preliminary foundation recommendations are presented below in the Pl'eliminGl), Design Recommendations section of this report. MAN-PLACED
FILL Some areas in the eastern part of Parcel 5-1 have been used as a dump area for construction debris probably from previous projects in the Battlement Mesa Development. In general,
the fills appear localized and relatively shallow, but the fills could be deeper in other palis of the development area. Observations in the field indicate that the fill material consists
mainly of mixed sandy clay with cobbles and boulders and construction debris consisting oflarge concrete blocks, rebar, corrugated steel, and PVC pIpe. The man-placed fill material observed
in this study is not considered suitable as structural fill and must be excavated prior to any construction in the proposed development area. The fill areas are further discussed in
the PreliminGlJ' Design Recommendations section of this repOli. CONSTRUCTION RELATED SLOPE INSTABILITY A steep drainage located in the northeast part of Parcel 5-2 may be an area of
concern with regard to slope stability. The slopes generally appear to be stable in the area. Job No. 105469 ~tech
" " -7 -However, some evidence of past slope failure was observed in the project vicinity. In consideration of long-tenn stability, we recommend that a construction setback of 25 feet
be maintained for structures built adjacent to steep escarpments. Slope stability considerations are further discussed in the Preliminal)' Design Recommendations section of this repmi.
DEBRIS FLOWS Debris flows have occurred near the development site during the last 75,000 years. The debris flows can be divided into two types: (I) larger, older debris flows from the
Battlement Creek drainage, and (2) smaller, younger debris flows occurring along larger tributary drainages, including Battlement Creek. Large Battlement C,'eek Debris Flows: Several
large debris flows have originated in the upper reaches of the Battlement Creek drainage basin and deposited on the fan surface. The upper reaches of the Battlement Creek basin comprise
about 10 square miles and attain a maximum elevation of roughly 10,400 feet. The entire upper reaches are underlain by slump blocks, talus and solifluction deposits. All of these materials
could provide abundant sediments for future debris flows under the proper climatic and hydrologic circumstances. The last large debris flow in the Battlement Creek drainage appears to
have occurred about 10,500 years ago during the Late Pleistocene. Small DebJ'is Flows: Subsequent to the deposition ofthe large, late Pleistocene debris flows, considerable stream erosion
has occurred on the fan. The present tributary drainages to the Colorado River were incised below the old fan surface at this time. Battlement Creek, Monument Gulch, and the gulch paralleling
the southern boundary of the Battlement Mesa development are the largest of the tributary drainages. At least three separate phases of debris flows and alluvial sediment deposition can
be identified at the mouths of the three larger tribntary drainages. Deposition of debris flow deposits and alluvial sediments has occurred periodically during the last 6,500 years.
The youngest deposits may have occurred later than 1890 A.D. Job No. 105 469
'. '. -8 -It is our opinion that the potential for large Battlement Creek debris flows in the future is very low and that no special precautions to protect the proposed development from
such large scale events are warranted. Smaller debris flows appear to have been confined in the narrow, deep tributary valleys, and do not have any appreciable lateral extent until they
diverge from the narrow valley onto fan surfaces near the Colorado River. A hydrologist should evaluate the drainage in the northeast pmt of Parcel 5-2 for possible impacts to the project
site and stability of the drainage channel. EARTHQUAKE CONSIDERATIONS The project m-ea could experience earthquake related ground shaking. Historic earthquake ground shaking in the region
has been moderately strong, but has not exceeded Modified Mercalli Intensity VI (Kirkham and Rogers, 1985). Modified Mercalli Intensity VI ground shaking should be expected during a
reasonable exposure time for the proposed development, but the probability for stronger ground shaking is low. Intensity VI ground shaking is felt by most people and causes general alarm,
but results in negligible damage to structures of good design and construction. Structures should be designed to withstand moderately strong ground shaking with little or no damage and
not to collapse under stronger ground shaking. The U.S. Geological Survey National Seismic Hazard Map indicates that a peak ground acceleration of 0.056g has a 10% exceedence probability
for a 50 year exposure time at the project site (Frankel and Others, 2002). This corresponds to a statistical recurrence time of 475 years. The region is in the 1997 Uniform Building
Code, Seismic Risk Zone 1. Based on our current understanding of the ealihquake potential in this part of Colorado, we see no reason to increase the previously accepted seismic risk
zone for the region. PRELIMINARY DESIGN RECOMMENDATIONS The conclusions and recommendations presented below are based on the proposed development, subsurface conditions encountered in
the exploratory borings by Chen and Associates (1982a and 1982b) and our experience in the area. The recommendations are Job No. 105469 ~tech
'. " -9 -suitable for plamling and preliminary design but site specific studies should be conducted for individual building development. FOUNDATIONS Bearing conditions will vary depending
on the specific location of the buildings on the propeliy. Based on the nature of the proposed construction, spread footings placed 011 the natural soils below the topsoil and any existing
fill should be suitable for the building support. We expect the footings can be sized for an allowable bearing pressure in the range of 1,000 psfto 3,000 psf. Foundations that bear entirely
on the underlying gravel soils can be designed for 3,000 psf. Expansive clay matrix or clay layers can be encountered ill the underlying gravel soils that lllay need to be removed or
the footings designed to impose a minimum dead load pressure to limit potential heave. Nested boulders and loose matrix soils encountered at footing grade may need treatment such as
enlarging footings or placing compacted backfill or COllcrete backfill. Foundation walls should be designed to span local anomalies and to resist lateral earth loadings when acting as
retaining structures. Below grade areas and retaining walls should be protected from wetting and hydrostatic loading by use of an underdrain system. The footings should have a minimum
depth of36 inches for frost protection. FLOOR SLABS Slab-on-grade construction should be feasible for bearing on the natural soils. There could be some post construction slab movement
at sites with collapsible matrix or expansive clays. To reduce the effects of some differenlialmovement, floor slabs should be separated from all bearing walls and columns with expansion
joints. Floor slab control joints should be used to reduce damage due to sln'inkage cracking. A minimum 4 inch thick layer of free-draining gravel should underlie basement level slabs
to facilitate drainage. Job No. 105469
", "/-10-UNDERDRAIN SYSTEM Although free water was not encountered in the exploratory borings, it has been our experience in the area that local perched groundwater can develop during
times of heavy precipitation or seasonal runoff. An underdrain system should be provided to protect below-grade construction, such as retaining walls and basement areas from wetting
and hydrostatic pressure buildup. The drains should consist of drainpipe sUiTOunded 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 lowest adjacent finish grade and sloped at a minimum I % to a suitable gravity outlet. SITE GRADING Grading for the subdivision development is
assumed to be relatively minor. Cut depths for the building pads and roadways should not exceed about 10 feet. Fills should be limited to about 10 feet deep and not be placed on slopes
that exceed about 40% grade. Structural fills should be compacted to at least 95% of the maximum standard Proctor density near optimum moisture content. Prior to fill placement, the
sub grade should be carefully prepared by removing all vegetation, topsoil and existing fill. The fill should be benched into slopes that exceed 20% grade. The on-site soils excluding
oversized rock, vegetation and topsoil should be suitable for use in embankment fills. Permanent graded cut and fill slopes should be sloped at 2 horizontal to I vertical or flatter
and protected against erosion by revegetation, rock riprap or other means. Rock obtained from on-site excavations will probably be suitable for used as riprap. This office should review
site grading plans for the project prior to construction. SURFACE DRAINAGE The grading plan for the subdivision should consider runoff from uphill slopes through the project and at individual
sites. Water should not be allowed to pond which could Job No.1 05 469 c;&I)tech
" '1 -II -impact slope stability, foundations and pavements. To limit infiltration into the bearing soils next to buildings, exterior backfill should be well compacted and have a positive
slope away from the building for a distance of at least 10 feet. Roof downspouts and drains should discharge well beyond the limits of all backfill and landscape irrigation should be
restricted within at least 5 feet offoundatiolls. PAVEMENTS SECTIONS The soils encountered at shallow depth typically consist of low to medium plasticity clays that are considered a
poor subgrade for suppOli of pavement sections. Roadway design information has not been provided but we assume the traffic loadings will be relatively light and typical of the plaJUled
residential development. Based on typical traffic loadings and a clay subgrade, pavement sections can be assumed to be 4 inches of asphalt on 10 inches of base course for collector streets,
and 3 inches of asphalt on 8 inches of base course for local streets. When the roadway design and traffic loadings are better known, we should conduct additional analyses for design
pavement section recommendations. LIMITATIONS This study has been conducted according to 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 field recol1l1aissance, review of
published geologic reports, the exploratory boring information and locations as shown on Figure 1, 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 (MOB C) 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 provided by the exploratory boring information
and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those Job No. 105469
~tech
'. " -12 -described in this report, we should be notified so that re-evaluation of the recommendations may be made. This rep0l1 has been prepared for the exclusive use by our client
for planning and preliminary design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation,
conduct additional evaluations and review and monitor the implementation of our recommendations. 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 ofthe geotechnical engineer. Respectfully
Submitted, HEPWORTH -PAWLAK GEOTECHNICAL, INC. Arthur D. Buck Engineering Geologist and by: ADB/ksw cc: Sclm1Ueser Gordon Meyer -Attn: Debbie Duley Job No. 105469 ~tech
'. °1 -13 -REFERENCES Chen and Associates, 1982a. PrelimiI1O!)! Soil and Foundation Investigation, Proposed Residential Development, Parcel 5-1, Balliement Mesa PUD, GG1:jield COllnty,
Colorado. Prepared for Battlement Mesa, Inc., dated June 8, 1982, .Tob No. 24,015. Chen and Associates, 1982b. Preliminary Soil and Foundation Investigation, Proposed Residential Development,
Parcel 5-2, Battlement Mesa PUD, Garfield County, Colorado. Prepared for Battlement Mesa, Inc., dated June 8, 1982, Job No. 24,014. Donnell, l.R. and Others, 1986, Preliminary Geologic
Map a/the Grand Valley Quadrangle, Garfield County, Colorado: U.S. Geological Survey, Miscellaneous Field Studies Map MF-1883. Frankel, A.D. and Others, 2002. Documentation/or the 2002
Update a/the National Seismic Hazard Maps. U.S. Geological Survey Open File Report 02-420. Kirkham, R.M., and Rogers, W.P., 1985. Colorado Earthquake Data and Interpretations 1867 to
1985. Colorado Geological Survey Bulletin 46. Widmartll, B.L., Kirkllam, R.M., and Rogers, W.P., 1998, Pre!imil1G1Y Fault and Fold Map and Database a/Colorado: Colorado Geological Survey,
Open-File Report 98-8. Job No. 105 469
o (]l ... Ol <0 GJI fTIfTI OLi -I::E fTlO 0;:0 I-I ZI 01 »Li r» • ::E -z»r 0;>:; C..J "0 1'---11 :;: r o G) UJ .o... , I'l X "1J r o ::u » -I o ;:0 -< aJ o ::u z G) UJ ...., .0. .c..
. CD N -.;.' a 5 10 15 20 25 BORING 1 29/12 WC=7.1 OO~BB.O -200~97 LL=31 PI-l0 60/9 BORING 2 15/12 12/6 -200~74 LL=56 PI~17 27/2 BORING 3 15/12 WC=16.B 00=100.4 -2~B7 LL=33 PI=12 38/9
BORING 4 16/12 19/12 WC=12.9 00=92.5 BORING 5 7/12 -200=96 LL-27 PI~9 17/12 WC~B.7 00-96.3 50/6 Note: Explanation of symbols is shawn on Figure 5. BORING 6 23/12 20/12 BORING 7 a 20/12
WC~20.9 OD~9B.3 -20~92 LL~41 PI=17 20/1 5 10 15 20 25 .C.J "-0 =r -;..' ~
o (]l -J>. (]) CD G)I fllfll O\J --1::;;: fllO O;u I--1 ZI 01 »\J .r »::;;: -Zr» f''' o (1) "0 1---11 :T r o Gl U1 o ""T] fll X -U r o ;u » -I o ;u -< rn o ;u Z Gl U1 ""T] <5' c ~ m
01 ..., <D -(1) o 5 10 15 20 25 BORING 8 16/12 WC=7.9 00=96.3 -200-92 LL-54 PI-18 15/6 13/12 BORING 9 25/12 WC=7.6 WSS-O.004 15/6 26/12 BORING 10 19/12 WC=11.3 00=90.3 -200=84 LL-29
PI-lO 25/11 WSS=0.05 32/12 BORING 11 13/12 25/12 43/9 BORING 12 14/12 16/12 WC=6.7 00=93.6 -200=89 LL-28 PI=9 16/5 Note: Explanation of symbols is shown on Figure 5. BORING 13 8/12 25/12
-200=81 LL=43 PI=18 WSS=0.019 15/2 BORING 14 47/12 27/12 o 5 10 15 20 25 o (1) "-0 ;;:,-." <D -(1)
o (]1 -J>. (J) <D ClI fTlfTl OlJ -I:::E fTlO 0:;u I-I ZI 01 »lJ r» -:::E -r z» 0;>;; o ""0 1----115= r o G) (j) o " fT1 X lJ r o ;;u » -I o ;;u -< OJ o ;;u z G) (j) ."0. .c.. , (1) -J>.
;;' CD ~ BORING 15 o 38/B 5 10 34/3 15 20 25 BORING 16 22/12 WC=9.B 00-90.7 -200=97 LL=34 PI-14 17/12 BORING 17 16/12 10/6 25/5 BORING 18 36/12 BORING 19 22/12 12/12 WC-B.2 00-77.6 -200-95
LL-33 PI-12 22/12 Note: Explanation of symbols is shown on Figure 5. BORING 20 16/12 21/12 WC-3.3 00-97.9 BORING 21 12/12 74/12 25/2 o 5 10 15 20 25 o ""0 ~ ::r ;;' CD ~
" LEGEND: ~ o ~.. . :6. :' . p ~ 29/12 T NOTES: TOPSOIL CLAY (Cl); silty to sandy and gravelly with depth, stiff to very stiff, porous, slightly to highly calcareous, dense to very dense,
slightly moist to moist, light brown. SAND AND GRAVEL (GC); with cobbles and boulders in clayey matrix, calcareous, dense to very dense, slightly moist to moist, light brown . Relatively
undisturbed drive sample; 2-inch 1.0. California liner sample. Drive somple; standard penetration test (SPT), 1 3/8 inch I.D. split spoon sample, ASTM D-1586. Drive sample blow count;
indicates that 29 blows of a 140 pound hammer falling 30 inches were required to drive the California or SPT sampler 12 inches. Practical Rig Refusal; where shown above bottom of log
It indicates that multiple attempts were made to advance boring. 1. Borings 1-9 were drilled April 21 and 22, 1982 for Chen and Associates Report No. 24,015. Borings 10-21 were drilled
April 22 and 23, 1982 for Chen and Associates Report No. 24,014. All borings were drilled with a 4-inch diameter continuous flight power auger. 2. laboratory Testing Results: WC = Water
Content ( % ) 00 = Dry Density ( pcf ) -200 = Percent passing No. 200 sieve 105 469 HEPWORTH-PAWLAK GEOTECHNICAL, INC. lL = Liquid Limit ( % ) PI = Plasticity Index ( % ) WSS = Water
Soluble Sulfate ( % ) LEGEND AND NOTES Figure 5
., Moisture Content = 7.1 percent Dry Density = 88.0 pcl Sample 01: Silty Cloy From: Boring 1 at 4 Feet 0 -2 N ~ Compression '-c upon .2 "-wetting Vl 4 "Vl '\ ~ a. E \ 0 6 () 1\ 8 10
0.1 1.0 10 100 APPLIED PRESSURE -ksl Moisture Content = 12.9 percent Dry Density = 92.5 pcl Sample 01: Sandy Cloy From: Boring 4 at 5 Feet 0 N 2 c V V Compression 0 ~ ·iii C. upon Vl
4 wetting "~ a. E ~ 0 ~ () 6 " 0 8 0.1 1.0 10 100 APPLIED PRESSURE -ksf 105 469 HEPWORTH PAWLAK SWELL-CONSOLIDATION TEST RESULTS GEOTECHNICAL, INC. Figure 6
., Moisture Content = 8.7 percent Dry Density = 96.3 pcf Sample of: Sandy Clay From: Boring 5 at 4 Feet 0 2 ~ ~ ( Compression upon 0::: 4 wetting a 'iii '\ .U,l .... a. '\ E 6 a \ C,)
8 1\ \ 10 0.1 1.0 10 100 APPLIED PRESSURE -ksf Moisture Content = 7.9 percent Dry Density = 96.3 pcf Sample of: Silty Cloy From: Boring 8 at 1.5 Feet 0 ~ 1 0::: c-p Compression a -...........
'iii ~ upon .U,l wetting .... 2 a. E '\ a C,) r\ 3 4 0.1 1.0 10 100 APPLIED PRESSURE -ksf 105 469 HEPWORTH PAWLAK SWELL-CONSOLIDATION TEST RESULTS GEOTECHNICAL, INC. Figure 7
, 'r Moisture Content = 11.3 percent Dry Density = 90.3 pcf Sample of: Sandy Silty Clay From: Boring 10 at 1 Foot 0 -2 ~ ~ /' Compression upon c: 4 wetting 0 'iii III "\ .". a. '\ E
6 0 \ () 8 1\ 10 0.1 1.0 10 100 APPLIED PRESSURE -ksf 0 -r-Moisture Content = 6.7 percent . r---2 1--, Dry Density = 93.6 pcf Sample of: Sandy Cloy From: Boring 12 at 4 Feet 4 ~ r--I':
6 ~ c: < !---'" Compression 0 'iii 1\ upon III .". 8 wetting a. '\ E 0 () 10 12 l\ 14 \ \ 16 0.1 1.0 10 100 APPLIED PRESSURE -ksf 105 469 HEPWORTH PAWLAK SWELL-CONSOLIDATION TEST RESULTS
GEOTECHNICAL. INC. Figure 8
, 'f Moisture Content = 9.8 percent 0 Dry Density = 90.7 pcf Sample af: Silty Clay From: Boring 16 at 1 Foot 1 ~ r-~ 2 I<: ~ ( Compression I: upon .2 3 '\ wetting II) \ II) '~" 0. E
4 0 u \ 5 \ 6 0.1 1.0 10 100 APPLIED PRESSURE -ksf Moisture Content = 8.2 percent 0 Dry Density = 77.6 pcf Sample of: Silty Clay ~ From: Boring 19 at 4 Feet 2 4 \' ~ \ "-I"-Compression
I<: upon 6 wetting I: 1\ a 'iii '~"" 0. 8 E 0 u \ 10 12 \ 14 0.1 1.0 10 100 APPLIED PRESSURE -ksf 105 469 HEPWORTH PAWLAK SWELL-CONSOLIDATION TEST RESULTS GEOTECHNICAL. INC. Figure 9
Moisture Content = 3.3 percent Dry Density = 97.9 pcl Sample of: Sandy Clay From: Boring 20 at 4 leet 0 ---r-. 1 Compression upon wetting 2 3 \. N I: \ a 'iii " 4 ".. f\ a. E a () 5
11\ 6 ~ 7 8 0.1 1.0 10 100 APPLIED PRESSURE -ksf 105 469 HEPWORTH-PAWLAK SWELL-CONSOLIDATION TEST RESULTS Figure 10 GEOTECHNICAL. INC.
• HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 1 Job No. 105 469 SUMMARY OF LABORATORY TEST RESULTS ! Paae 1 of 2 SAMPLE LOCATION NATURAL NATURAL GRADATION PERCENT ATTERBERG LIMITS WATER
MOISTURE DRY GRAVEL SAND PASSING LIQUID PLASTIC CLASASAISFHICTAOT ION SOLUBLE SOIL OR BORING DEPTH CONTENT DENSITY NO. 200' LIMIT INDEX SULFATES BEDROCK TYPE (%) (%) SIEVE (ft) (%) (od)
(%1 -<%) (%) 1 4 7.1 88.0 97 31 10 A-4 (10) Silty clay 2 4 74 56 17 A-7-5 (15) Sandy clay 3 1 16.8 100.4 87 33 12 A-6 (10) Sandy clay 4 5 12.9 92.5 Sandy clay 5 2 96 27 9 A-4 (7) Silty
clay 4 8.7 96.3 Sandy clay 7 1 20.9 98.3 92 41 17 A-7-6 (18) Silty clay 8 11/2 7.9 96.3 92 54 18 A-7-5 (22) Silty clay 9 1 7.6 0.004 Sandy clay ,
• HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 1 Job No. 105 469 SUMMARY OF LABORATORY TEST RESULTS ~ Paoe 2 of 2 SAMPLE LOCATION NATURAL NATURAL GRADATION PERCENT ATTERBERG UMITS WATER
AASHTO MOISTURE DRY GRAVEL SAND PASSING UQUID PLASTIC CLASSIFICATION SOLUBLE BORING DEPTH CONTENT DENSITY NO. 200 UMIT INDEX SULFATES BEDSROOILC KO TRY PE (%) (%) SIEVE (It) (%) (Dcf)
(%) (%) ~(%L 10 1 11.3 90.3 84 29 10 A-4 (7) Sandy silty clay 4 0.050 Sandy clay 12 4 6.7 93.6 89 28 9 A-4 (7) Sandy clay 13 5 81 43 18 A-7-6 (15) 0.019 Sandy clay 16 1 9.8 90.7 97 34
14 A-6 (14) Silty clay 19 4 8.2 77.6 95 33 12 A-6 (12) Silty clay , 20 4 3.3 97.9 Sandy clay -
EXISTING PUMP STATION Explanation: af Qal Qc Qaf Man Placed Fill . Valley Floor AllUVium Colluvium b. Fan Alluvial Fan/De ns • BORING 1 ACpopnrtoaxcitm: ate b ou ndary of map units.
. Boring: tions of exploratory borings dnlled Approximate loca ciates (1982). by Chen and Asso APPROXIMATE ~CAlE: 1" = 300 ~t~~~HNJCAL WORTH-PAWLAK H~ 52 RCElS 5-1 AND -CEMETARY PA G
lOCATIONS NO BORIN GEOLOGY MAP A FIGURE 1 105469