r'··gmw.consrv.ca.gov/shp/apsi_siteinvestigation... · 6/27/1975 · .dth district thomas...

David W, C•rp•nter County of Al•meda · Public Works Building RoC!lll ' "1 399 Elmhurst Street H•yward, California 9451i4

Daar Hr, Carpenter:

·-··

r'·· <--·

(415) 557-0413

No'lelllbllert, 1976

Thcl Terrasearch lnwstlgatlon for the Krudop homeslte; Pleasanton, has been received and placed In our Informal Con$Ultlng file,

Thanks for your consideration,

EWH/mkr

.. -····--·-""':!• ·---··-- ·~------------ .. ·~-- -~

Slnc:e.-.ly yours,

EARL W, HART Geologist San Francltco District Office

•

COUNTY ! . -

OF i' ALAMEDA AlAM!DA COUNTY

PUBLIC WORKS &UILDING ROOM 141

399 ELM HURST STREET HAYWARD, CALIFORNIA 94S44

881-6423

Mr. Earl W. Hart California Division of

Mines and Geology FeJ:>ry Building San Francisco, Ca 94111

Dear Mr. Hart:

Octobel:' 25, 1976

BOARD Of: SUPfRVISO~S

JOHN D. MURPHY lST DISTRICT

CHAl?C.ES SANTANA 2ND DIS'fl~ICT

f=RED F. COOPER 3RD DJSTRJCT

JOSEPH P. BORT .dTH DISTRICT

THOMAS H. BATES 5TH DISTRICT

HERBERT C, C:ROWlE DJRJ;CTO~ Of PU8UC WORKS

Enclosed is a copy of a Soil and Geologic Investigation report prepared for a single family residence on Foothill Road, Pleasanton area of Alameda County. The report was requiJ:'ed under provisions of Chapter 29, Alameda County Building Code and meets the requirements of the Code. It was not reviewed for conformance with the guidelines for geologic reports under the Alquist-Priolo Act but since the report does provide geological observations in close proximity to the Calaveras Fault, this extra copy is being sent to you for filing and use as may prove appropriate.

The site location, as shown on Figure 2 in the report, is on the east side of Foothill Road, about 2,200 feet south of the intersection of Foothill Road and Castlewood Drive, Dublin, California 7-~ minute quadrangle.

VeJ:>y truly yours,

fl~ w ~~L\ DWC :gh David W. CaJ:>penter

Alameda County Engineering Geologist

ALAMll:CIA "' AL•AH"~ .. 111~ .. KIELKV .. EM~R'rVILLE • F~~"'Of'(T • H.o.vwo11i1110 • l,.lvEftl,(ORIC ill i'IEW.O.RIC • OAKLANti • P!~OMOMT • PLll:"i;S;ANTON

•

•

•

•

•

•

•

•

•

•

•

SOILS AND GEOLOr.Ir. INVESTIGATION on

PROPOSED HOH!lSITE Foothill Boulevard

Pleasanton, California

for

MR. KRUDOP (c/o Allied Brokers) D,, ";s '·1

By

TERRASEARCH, INC • Project No. 1273-E

•

•

•

•

•

•

)

)

TERRASEARCH, INC.

SOIL, FOUNDATION AND GEOLOGICAL. ENGINEERS

1580 NORTH rouATH $TAE:ET SAN JOSE, CALIFORNIA 95112 (408) 287-9460 2129 HACIENDA WAY SACRAMENTO, CALIFOFINIA 9582.5 (916) 4B3.-8402

Mr. Dan Gamache c/o Allied Brokers 3730 Hopyard Road Pleasanton, California 94566

Subject: Proposed l!omesite Foothill Road Pleasanton, California

Project No. 1273-E 11 March 1976

ADDENDUM TO SOIL AND GEOLOGIC INVESTIGATION

Dear Mr. Gamache:

In response to your request, TERRASEARCH, INC., has reviewed and republished our report for the prcpo~ed homesite on Foothill Road. We find that the current building concept is feasible.

The relocation of the house to a more easterly location is, from a seismic hazard vie1<point, an improvement. However, the relocation of the home, when considering the aspect of f oundati.on design, requires some additional considerations be met. The relocation of the house will place the foundation at or near the banks of the abaudoned stream channel near the rear of the original homesite. A certain amount of uncompacted fill has been placed along this bank.

If foundations are placed in or near this bank, the fill should be removi=d, the native ground prepared, and the material replaced as compac:ted fill in accordance with Paragraphs 6 through 10 of the enclosed report. As an alternate, deep pie.r foundations should be used in this area.

The pters should penetrate the fill and be excavated a mlnimum of five feet into the firm natural ground benenth the fill. All other design and construction factors should be in accordance with Paragraph 13 of the enclosed report.

•

•

•

•

•

•

•

•

•

•

Project No. 1273-E 11 March 1976

It is our opinion, based on the data gathered, that the site is sa·fe from landsliding providing that the nature of the site remains the same and that the recommendations of this report and letter are followed~ The settlement of any fills placed in accordance with the provisions of this report should be negligible, The fill noted along the stream will settle under stresses, possibly beyond the limits of structural tolerances. Recommendations to minimize this effect have been given.

In the case of unusual storm activity, some flooding and erosion may be anticipated along the old stream channel, It is recommended that the recommendations of the Flood Control District be followed.

Should ·you have any questions concerning the contents of this report 'or should additional information be required, please contact this office at your convenience .

Reviewed by:

CM:HA:ld

Copies: 2 to Hr. Dan Gamache

2

Very truly yours, TERRASEARCH, INC.

~ ")/l.Uv.J<A1 Curtis ifessing f; E.G. Senior Enginee.ing Geologist

Hassan Amer, P.E. Principal Engineer

•

•

•

•

•

•

•

•

•

•

TERRASEARCH, INC.

SOIL, FOUNDATION AND GEOLOGICAL ENGINEERS

1580 NORTH FOl,JRTH STREET SAN JOSE, CAUFOFINIA 95112 (408) 287-9460 212S HACIEi:NDA WAY SACRAMENTO, CAl.IFORNIA 9582~ (918) 483-9402

Mr. Jerry Krudop c/o Allied Brokers 3730 Hapyard Road Pleasanton, California 94566

Subject: Proposed Homesite Foothill Boule.vard Pleasanton, California SOIL AND GEOLOGIC INVESTIGATION

Dear Mr. Krudop:

Project No. 1273-E 27 June 1975

In response to your authorization, TERRASEARCH, INC., has completed a Soil and Geologic Investigation on your proposed homesite located in Pleasanton, California.

The data gathered during our investigation indicates that the site is not crossed by any tract of the Calaveras Fault and that the site may be developed for the construction of a single-family, one or two-story frame residenco. This feasibility is based upon adhere11ce to the design and construction procedures as outlined in the enclosed report.

Should you have any questions concerning the contents of this report, please contact this office at your convenience .

CM:HA:mer cc: Mr. J~rry Krudop (4)

Very truly yours, TERRASEARC!I, TNC.

~b;-Curtis Messinger -'-1 C.E.G. 674

Hassan Amer R.C.E. 19674

•

•

•

•

•

•

•

•

•

•


TABLE OF CONTENTS

LETTER OF TRANSMITTAL

SOIL AND GEOLOGIC INVESTIGATION

Purpose and Scope Proposed Construction Methods of Investigation Surface Soil Conditions General Geology Site Geology

DISCUSSIONS AND CONCLUSIONS

Conclusions

RECOMMENDATIONS

General Grading of the Site Foundations Perimeter Footings & Interior Spread Footings Pier and Grade Beam Foundation Systems Concrete Slabs-on-Grade General Construction Requirements

LIMITATIONS AND UNIFORMITI OF CONDITIONS

LITERATURE RESEARCH

APPENDIX A

Site Plan (Figure No. 1) Location & Geology (Figure No. 2) Logs of Test Borinr,s (Figures No. 3 and 4) Summary of Lah Test Results (Table 1) Aerial Photo Lincation (Figure No. 5)

APPENDIX B

Geophysicist's Report

Page No.

1 1 1-4 4 4-5 6

7

8 8-9

10 10 10-11 11-12 12

13

14

16 17 18-19 20 21

•

•

•

•

•

•

•

)

•


SOILS AND GEOLOGIC INVESTIGATION

Purpose and Scope

The purposes of this investigation were:

a) To determine if any active branch of the Calaveras Fault crosses the proposed homesite;

b) To provide those design data determined by geologic and soils conditions which are necessary for completion of the project •

The data used in the analysis phase of this investigation were gathered by

means of a study of geologic maps, aerial photographs, test borings, and

laboratory •

Proposed Construction

At the time of our i.nvestigation, the construction of a two-story,

wood-frame house was anticipated •

Methods of Investigation

In addition to a reference to the available literature on the site

and its environs, the project site was studied by means of stereoscopic

inspection of aerial photographs test borings, geophysical exploration,

and laboratory testing.

Aerial Photograph Study_: The aerial photographs use.d in this study were

flown in 1957, and printed at a scale of one-inch equal to 1,000 feet.

These photos were studied under thi= St<'.reoscope for lineaments (indicative

of faulting), landsliding, seepage areas, areas of potential ins tahility,

and any other pertinent features •

1

•

•

•

•

•

•

•

•

•

•

•


Subsurface Exploration: The subsurface exploration was accomplished by

~ans of a truck-mounted earth auger utilizing a six-inch diameter bit •

The purposes of this exploration were as follows:

4) to determine the subsurface stratigraphy on the site; and

b) to obtain soil and/or rock samples for testing in the laboratory .

Undi$tYrbed soil samples were obtained by hydraulically pressing or ·

6riving t:he sampling device into the undisturbed material at the bottom

of the drill ho:e. These samples were sealed in tubes and forwarded to

the laboratory for testing. All drilling was done under the supervision

of a member of our staff •

The locations of the borings are shown on Figure No. 1, and the "Log

Qf !eH Borings" is given as Figure No, 2, Appendix A •

Geophysical Exploration: Allied Geophysics of San Jose was retained in

order to supplement the information gathered during the trenching and

~ite inspection. The geophysicist's report is reproduced in its entirety

as Appendix B of this report. The conclusions of the ge.ophysicist were as

follows:

No fault trace was detected •

2

•

•

•

•

•

•

•

•

•


Laboratory Testing: The laboratory testing for this investigation was

progrannned to evaluate the on-site soils in relation to bearing values,

and other design criteria determined by soil and/or geologic conditions.

The following tests were used:

Moisture-Density Determinations: These determinations are performed

from the volume weight ratios of the particular samples ·before and after

oven drying. The natural moisture and density, or unit weight, of the

subsurface mate.rials is basic to the determination of strength parameters

and grading criteria •

Unconfined Compressive Test: Determined usually on soft to stiff

clays. It is approximately equal to twice the shear strength of the

clays tested and is performed by axially stressing a sample to the failure

point, The failure stress is indicative of allowable foundation bearing

value, and is used in the determination of slope stability determination •

Direct Shear Test: This test is performed by ;:angentaly stressing a sample

under progressive normal loads. It is also indicative of shear strengths.

Atterberg Limits Determinations: Atterberg Limits are determined by the

correlation of consistency changes with 1noisture changes. The Plasticity

3

•

•

•

•

•

•

•

•

•

•

•


Index, a direct derivative of the Atterberg Limits, is indicative of the

expansion potential of the soil tested •

The results of the laboratory testing are given in Table I. In addition,

the natural moisture contents and dry densities are presented in the Logs

of Test Borings.

Subsurface Soil Conditions

The homesite is, according to our borings, unlain by silts and clays in

the near surface areas. Below this are found sandy, silty Clays with

some gravels typical of buried channels 1rnually found in alluvial plains .

The water level in boring No. 2 was found to be at a depth of 19 feet.

General Geology

Helly et al indicate that the site i8 underlain by "young fluvial deposits

consisting of a variety of unlithified granular to colloidal, locally

drained sediments. These sediments on the site itself are, from all indi-

cations, a combination of flood plain deposits related to the ephemeral

stream which crosses the prop,,,rty and co;_luvium generated by the hillside

to the west .

The site is within the special studies zone as designated by the California

Division of Mines and Geology in conformance with current directives. 'l'his

4

•

•

•

•

•

•

•

•

•

•

•


zone is defined by a bond and on either side of the mapped traces of the Calaveras

Sunol Fault. In the area under investigation, two traces have been mapped •

This does not necessarily indicate that two traces of the fault are present.

It does indicate, however, that two researchers have placed the fault along

two lines and therefore the exact locaticn of the Calaveras Fault is in

doubt.

Hall (1959) has placed the Calaveras Fault as sub-parallel to Foothill

Road and possib~y just west of the street in the area of the proposed

building. The special studies zone map places a possible trace of the

fault along the eastern edge of Foothill Road. This postulated trace was

evidently drained from Ford's Groundwater St:udy of the Pleasanton, Sunol

and Livermore Valleys (see Figure No. 2).

To summarize, no available published maps indicate that the proposed

homesite is crossed by a trace of the Calaveras Sunol Fault .

5

•

•

•

•

•

•

•

•

•

•

•

Site Geology


The borings drilled for the foundation investigation phase of this study

tended to confirm the mapped Late Cenozoic Geology of the site.

Dui:ing the study of aerial photographs of the area, which was performed by

Murray Levish in consultation with Terrasearch, Inc., (October, 1971), a

lineament crossing Oak Lano was noted. This was mapped as approximately

SO feet to the west of Foothill Road. This lineament has been plotted

on Figure No. 5 which is a print of an infra-red photograph made in 1972 •

Burton Rose (personal communication) indicates that the Calaveras Fault

passes through the slope at Castlewood Country Club and passes through

the barn across the site and, hence, to the south. This corresponds· with

observed lineaments •

During the geophysical phase of this study, the traverse was so located

as to cover the buildable portion of the site and extends into the right-

of-way of Foothill Road beyond setback requirements .

No indications of faulting were noted on the site in the area between

Foothill Road and the creek channel. If a normal setback from Fo"thill Road

is used, the house. will be a minimum of 50 feet from any active fault as

defined by geophysical means. This data is confirmed by the test. bori.ng

data .

6

•

•

•

•

•

•

•

•

•

•

•

Project No, 1273-E 27 June 1975

DISCUSSIONS AND CONCLUSIONS

The conclusions derived from this study are:

1) There is no evidence from the techniques used which would indicate

that a fault crosses the part of the site studied,

2) The house will be located in a seismically active area. Earth-

quakes may be expected along the Calaveras Fault; and, although all evidence

indicates that the house is outside the expected rupture zone, accelerations

in excess of O.? g. may be expected.

3) A certain amount of risk is involved in any building project in

the San Francisco Bay Area. However, the construction of a well-founded,

properly constructed structure should tend to minimize such risks •

7

•

•

•

•

•

•

•

•

•

•

•

General


RECOMMENDATIONS

1. It is our conclusion, based upon the geophysicist report, that no

active trace of the Calaveras Fault crosses the proposed building site •

2. The site may be developed for the construction of a single-family

one or two-story frame dwelling providing design and construction are

accomplished in accordance with the recommendations given in this report.

3. It is anticipated that no differential settlement will occur during

the life of the structure,

Grading of the Site

4. Other than that necessary to establish the building pad, the grading

should be limited to what is absolutely necessary to assure proper surface

drainage and ininimi;,:e disturbance of the existing hill.side slopes •

5. The Soil Engineer should be notified a minimum of two working days

prior to the commencement of clearing or grading operations in order that

he may coordinate the work in the field with that of the grading contractor

and review site conditions as related to the proposed grading.

6. All organic growth, contaminated topsoil, and other debris should be

8

•

•

•

•

•

•

•

•

•

•

•


removed from the building pads, driveways, and parking areas prior to the

grading operations. The depth of contaminated topsoil may vary between

2 to 4 inches,

7. After stripping, the next six inches of native soil should be scarified,

moisture conditioned as necessary, and recompacted to a minimum of 90%

relative compaction based on ASTM Test Procedure Dl557-70.

8. After the surface areas are prepared, fill, if required, shall he

placed in layers which when compacted shall not exceed six inches in

thickness. Each layer shall be compacted to 90% relative compacotion

based on the aforementioned compaction standards •

9. If any import material is to be used for fill, it should be approved

by the Soil Engineer prior to being imported to the site. If import

material should be required, it must, therefore, meet the following

recommendations:

a) Have a plasticity index of less than 10;

b) Have not more than 15% passing the No. 200 sieve;

c) Have an R-Value of not less than 25 •

9

•

•

•

•

•

•

•

•

•

•

•

Foundations


10. The proposed structures may be supported on continuous perimeter and

isolated interior spread footings or on friction pier and grade beam

foundation sys terns •

Perimeter Footings and Interior Spread Footings

11, A spread.footing type foundation system may be used to support the

·residential structure. These footings shall be founded a minimum of 12

inches below lowest adjacent grade and be a minimum of 12 inches wide.

12. An allowable bearing capacity for the continuous and isolated spread

footing foundations of 2, 000 p, s, f. for dead plus live loads may be used.

For the above conditions, the bearing capacity value. may be increased by

one-third to include short-term seismic and wind effects •

Pier and Grade Beam Foundation Systems

13. Concrete friction piers having a 12-::.nch minimum diameter could he

used to support the residential structure. The piers should have a minimum

depth of five feet below the lowest adjacent grade. All pier holes should

be thoroughly cleaned prior to placing the concrete. E'1ch vier should be

reinforced wi.th a minimum of two No. 4 bars for the full length and the

10

•

•

•

•

•

•

•

•

•

•

•


reinforcement should extend to tie into the top steel of the grade beam •

Grade beams should be founded a minimum of six inches below final exterior

grade and must be reinforced with a minimum of four No. 4 bars, two in top

and two in bottom. Provided the foregoing conditions are !\let, an allow-

able skin friction design value of 400 p.s.f. for dead plus live load may

be used for design purposes. The allowable design value may be increased

by one-third to include temporary effects of seismic and wind. loading .

No design friction value should be assigned to the upper 12 inches of

embedment •

Concrete Slabs-on-Grade

14. All concrete slabs-on-grade should be placed on a minimum of 4-inch

layer of clean course sand, clean crushed rock, or a mixture of sand and

gravel, in order to serve as a capillary break and cushion layer. Where

floor covering is anticipated, the use of a visqueen-typc barrier is

recommended to reduce moisture condensation beneath the floor covedng .

A two-~_nch layer of sand may be placed over the visqueen barrier to

facilitate the placement of concrete without damage to the barrier and to

help in the curing of the concrete. It is suggested that prior to placing

t:he concrete slabs, the subgrade soils should be presoaked until a moi.sture

equilibr:ltutn condition is reached. 'l'he concrete slabs should be rei.nforced

with a minimum of wire mesh, however, due to the difficulty of proper

11

•

•

•

•

•

•

•

•

•

•

•


placement of the wire mesh within the center of the slab, the equivalent

bar reinforcing is preferable,

General Construction Requirements

15. The compaction of trench backfill within .the building and parking

area should be to the same degree of compaction as the engineered fill

adjacent to the trench. No jetting of trenches should be permitted without

prior approval of the Soil Engineer •

16. The surface soils on the site possess low expansive characteristics.

Therefore, continuous roof gutters are optional. It should be noted, how-

ever, that run-off water should be dischnrged away from the house founda-

tions, lf gutters and downspouts are incorporated, splash blocks should

be used •

17. Care must be exercised in the location of all improvements so that

the natural drainage is not blocked •

18. Project plans should be reviewed by the Soil Engineer for compliance

with the recoilliilendations of this report before construction begins •

12

•

•

•

•

•

•

•

•

•

•

•

LillITATlONS AND UNIFORMITY OF CONDITIONS

1. The recommendations of this report ure bused upon the assumption that

the soil conditions do not deviate from those \lisclosed in the borings and

from a reconnaissance of the site. If any variations er undesirable condi

tions are encountered during the development of the site, TERRASEARCH, INC.,

should be notified so that supplemental recommendations may be given •

2. This report is issued with the understanding that it is the responsibility

of the owner, or of his representative, to ensure that the information and

recommendations contained herein are brought to the attention of the Archi

t.ect and Engineer for the project and incorporated. into the plans, and that

the necessary steps are taken to see that the. Contractor and Subcontractors

carry out such recommendations in the field •

13

•

•

•

•

•

•

•

•

•

•

•

Literature Research


The research of literature included reference to general geologic maps of

the area, soil rnaps and geologic and soil reports issued for the development

of nearby projects. The specific references were as follows:

1. Brown, R.D., Jr., and Lee, W.11.K., "Active Faults and Preliminary

Earthquake Epicenters· (1969-1970) in the Southern. Part l'f the San Francisco

Bay Region." U.S. G. S. Misc. Field Studies Map FM-307 (HUD Basic Gontrib:.1tion

30), 1971.

2. Hall C.A., Jr. "Geology and Paleontology of the Pleasanton Area,

Alameda and Contra Costa Counties, California." Cal. University Cal. Publica-

tions in Geological Science, Vol. 34, No. 1, 1958.

3. Helley, E.J., Lajoie, K.R., and Burke, D.B. ,"Geologic Map of Late

Cenozoic Deposits, Alameda County, California." U.S.G.S. Misc. Field

Studies Map MF.429, 1972.

4. Reynolds and Associates, "Soil and Geologic Investigation, Th".ee Acre

Parcel, Southwest Corner, Foothill and Oak Lane." Project No. 426-1, August

1971.

5. Rogers, T. H. , "Gen:;.ogi~ Map of California , San Jose Sheet. n Calif-

ornia Division of Mines and Geology, 1968 .

14

•

•

•

•

•

•

•

•

•

•

•

APPENDIX A

Site Plan

Location & Geology

Logs of Test Borings

Summary of Lab Test Results

Aerial Photo L'lneation

•

•

•

•

•

•

•

•

•

• FOOTH1 LL

•

rm • •

I • • I •

~i 0.

<)>

-~~ ., g

':'. : i 11 ~~

• • -~<( j • • l~

<i:

]_ (>

Project No. 1273~E

27 June 1975

scci\e: 111• so1

--=.!-=..-·····-·-

ROAD

•

• t -N-

•

•

•

•

•

•

•

•

•

I r:.:...---:-T~-·.::-:::.;.-_L::..-:::.::.:.-.~: ... · ·.·'- ·-·=-~:~ :r:-:::::::=.y.::.:.:.:..:·-:: ·_ · ·· -·:::- :-·.

P~0ject No. lL/_~ .. 27 June 1975

·----····--··--- ··--.. ···----·--··-·--··· :~i:.~ ... .. ·-·-· -· ..... - ..... ---·· - -~: ··::. -::~·.::;:~ ... ]

: . . . ··-------·--· ;,. : .. ~ . .. ~ : ... ............. ·: .... :· _,

F'JOURE NO. - 2 LOCA'l'ION N ,-,

•

•

•

•

•

•

•

LOGGED BY CM DATE DRILLED

SOIL DESCRIPTION

ELEV. 305 J,

- -- 1 -- - 1-1

" ' I-' I'. Light brown Clayey SILT, hard, '" '" moist

I- z - / , ' ~ - - '

L. 3 - ' / /

I- - 1-2 '- 4 -I- -

I• Dark broton Clayey SILT, trace hard, slightly moist. ,,

, '- 5 - ,

/ /

'- - , ,

'- 6 - 1. '-,,


BORING DIAMETER 6"

slightly 4. 5-1

of sand, 4. 5-

- ~ L Dark hrown CLAY, some Gravel, slightly L.. 7 - 1

• moist, medium dense. ,_

L.. 8 -

L.. 9 -

--

:~vi.' ,_ .. ~ rA"

- ,, ) v

- 10 - IY~

106

105

BORING NO. 1

7

19

MISC. LAB

RESULTS

1. 5 04 24 '- - ~ Grey and brown mottled silty CLAY, moist, -11 - 1-31/ '' medium stiff - - I/}

-12 -- --13 - -

- -- 14 - -

Clayey SAND, moist.

. - -

•

•

, ~ 0 •

- -~ -'- -'- -~ -L -

I- -

L •

L -

I- -

L -

'- -L -

L -

Boring terminated at 16 1

*Ref. Topographic Survey by Creegan & D'Angelo

I FIGURE NO. 3 Log of Test Raring

• Project No. 1273-E

27 June .!..12.9.!..7-'"'i----------------. LOGGED BY CM DA TE DRILLED BORINO DIAMETER <" BORING NO. 2

• t,

h- 1 -,, ,, I/

• ... 2 - " " ·,, h- - 2-1 " h- 3 -

j

" • ... - , .... 4 -.... -• .... 5 - ,, h- -

.... 6 - 2-2 ,,, h- - , ,, , .... 7 -· - - I>.;_

• 8 - ,-3 I i1".1~ h- f1 .... - .,-

1,;. ~.

h- 9 - V•-1:.; ... - U1:,..

h- 10 - I~ i,;" . L - ")

• L_ 11 - ~: ,_ -L 12 •

r;:, ~~ L -

L_ 13 - r~,V. I

h- - bt-1 • .,, ~ 14 - (; f I'

... - ~-h- 15 -... -

.... 16 -- -• '-17 -L -'-18 -L . h-19 - . L -h-20 • .... . L -.... -L -

• ... -

-... .

.... .

SOIL DESCRIPTION

ELEV. 305

Dark grey-brown Silty CLAY, slightly moist, very stiff

Mottled grey and brown Clayey SILT, s tif £, 111ols t

Dark brown CIAY'with Sandstone Gravel, ~lightly mu is t, ttlcdium dense

Grey and brown mottled

Some Sund lcnsc

GRAVEL, roun<lec.l, st re.am nlluvi u1n

Boring tc.rininat~<l at 20 fe.et.

"Ref. Topographic Survey by Creegan & D' Ange. lo

3. 5 101, 17

103 14

105 19

I FIGURE NO. 4 - Log of Tes L Boring

19

MISC. LAB

RESULTS

•

• Hole Depth Dry No. Density

(ft.) (p.c.f.)

• 1-1 106.2

• 1~2 104.8

1-3 103.8

2-1 104.0

• 2-2 102.5

2-3 104.8

•

•

•

•

•

•

TABLE I

Project No. 1273--E June 27. 1975

Summary of Laboratory Test Results

}!oisture Atterherg Limits Unconfined Content Liquid Plasticity Compressiv"

(% Dry wt.) Limit Ind"" Strength (%)

6.9 27,4 10

29.3

23.5

17.l

14.0

18.5

7.0

.Direct Shear Cbhesion Angl" of (p.s.f.) Internal

Friction (de~r"e2

250 32°

•

•

•

•

•

•

•

•

•

• l .. ,.. I J. l ' ' ''j : ' :. ) '

____ _J

•

•

•

•

• APPEllDIX B

• Geophysicists Report

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

R. i3,,,t.,., Q.,,., i\LA . GEOL,QGl~"f

E"IGINEEAIN~ Gl;C('Jl..OGiST

IC: ...... ,,_.O~NIA RE.GISTRATIQN)

ALLIED Gt:OPHYS!CS

P.O. Box 5B3 .$AN .,.1¢~C:, CA. 9=.ii.1Q.1$ (40Q) ::!~0-2608

Terrasearch, Inc. 1580 North 4th Street San Jose, California

June 9, 1975

Attention: Mr. Curtis Messinger

Gentlemen:_

Project: Seismic refraction survey 1273-E

At vour r·equeti"L, a tiinqie fevc:1~t:U 1~cu1U~U l.y!Jl.! se1smfc rerract1on 11ne ~~s run a~ ~ne subject proper~y;. as placed on the cuurtesy plot plan provided.

Tt1e primary purpose was the detection, If pres.o·nt, of any fault trace crossing the parcel along the typi~al regional strike of N~-SE. No fault trace wa9 detected, as judged by the absencie of any low velocity gouge zone, abrupt changes in underground horizon elevations, or any abrupt horizontal velocity change.

Three underground v~iocity ranges were found:

v, , 200-1500 ft. per sec.

v2 3000 II 11 " V3 5800-6200 " " 11

Tho above data ls shown on the accompanying plate. The Time-Distance lower gra1h measures time In ml I 11-seconds and distance In feet per second. The upper half shows a cc~nputed profi I e section •

Thank you for the ooportunity cf conducting this study. Pl2ase call me if tncre are any qu-ostions.

R cs p e ct f u I I y s u bm i t t e d ,

-··----~____,..,......_ ------·--ll. 8urt<.1n HO~ie G.1-, J97

10 cc .

_, -"

-' -·

,_ . ~ ~--; ____ _

' " '11

!;:: ,---

' . i:

~.::; i -

--. ·-

,_

; .

---' I 1-,

"i ,-

1

-' .. 1.

- '

I ' ' 1-

i:

. ,

.!

.,

: -· .;

.:!

' _, ··1

.. , '··

i·

:.·

...... ; .;:. -.·l

1-, 1·

'

.;· ' - '

••j•: ::i ' ·r. .::· ::

i .. ,.

i

•

r '. . .. : I

,.

~. ,. :...:.:·· ,.

' ... ::

·j

.:::

....

. ~ : : :

' I> !,

,_ ·' ' .:!.

• ' , .

.,

i••

·' ' ' ' - . •:,

;;:

: .~ ! :

i.··

• ,.

' -l··

./.~...J

• ··:

;· ... i,

.j.

•' ! ! t.

r·: ~~_,,,·,:;// ... ..::=;:rs-~- ~ -- -- - - - - . -·-···- ----·---" --· --·-~~~--

• • u

,. .. !:

:o ____ ~· l-

''i

-: :,:

.. ~

!·

'· ..;

I ,.

,;1

I ! ! -j

'I 'I

1

• • • • • • •:· • • i . ' '

' ' ' ;

I

------------------------··· I •

! '

' ' '

' ---,-;--0--------------·-·----_.... ,q~ i4 -- l \) '

~ l,.__ ______________ _ r ; I

I j i

''

c $0 I I 1-::L...t:::r--_-----i-----....,

100 / J

s-~/ ~ c;:c

! '

- . U ?~O>r· .. /''1 73 /-!' Y/a.s;e,,,y , / ,, '-' ""

i!--A---·· '-B 2·hl ft. Seismic Refraction Line

i

r'··gmw.consrv.ca.gov/shp/apsi_siteinvestigation... · 6/27/1975 · .dth district thomas...

Documents