&t:t# 7/;e7/77 - California€¦ · 9/8/1977 · °'m"ate of califor:nia.~thf resources agf:ncy department of conservation etsmund 0. bl{own jfl:., g1;1ve,nor division of mines and

&t:t# 7/;e7/77

... ~' . .. ' ' __ ,

.,. °'m"ATE OF CALIFOR:NIA.~THf RESOURCES AGf:NCY

DEPARTMENT OF CONSERVATION

EtsMUND 0. Bl{OWN Jfl:., G1;1ve,nor

DIVISION OF MINES AND GEOLOGY DIVISION HEADQUARTERS RESOURCfS BUILDING, ROOM 1341

1'16 NtN'TH STRE!:T

SACRAMENTO, CA 9.5814

District Offi,eto LOS ANGELES Junipero Serra Bldg., Rm. 1065 107 South Bro(ldVf<!y 90012

Mr. Richard Glenn Planning Analyst City of Pleasanton 200 Bernal Avenue P.O. Box 520 Pleasanton, CA 94566

Dear Mr. Glenn:

SACRAMENTO Rl!liOurtlH Bld9,, Rm. l le 1416 Ninth Street 9.581.4

flf 730

SAN FRANCISCO Ferry lh1ildin9 94111

May 12, 1978

~ -

This is to acknowledge receipt of the 10 reports (identified) on the attached list) submitted with you; letter of May 8, 1978. Reports 1 to 5 have been reviewed on behalf of the City as requi;ed under the Alquist-Priolo Special Studies Zones Act and will be placed on open file. Report 6 will be filed when we receive the "Supplemental Report, Prnl iminary Fault Location Study dated December 27, 1977."

Reports 7 to 10 we;e for projects within the Special Studies Zones but were not reviewed as required. According to the November 22, 1977 letter of D.W. Carpenter, development was underway o; already completed when he was asked to review reports 8 to 10. There is no co•respondence rega ;ding report 7.

Based on these reports and the review conrnents of Mr. Carpenter, it would appear that the City of Pleasanton was not complying with the AlquistP;iolo Act prio; to late 1977. Enclosed Is a copy of Special Publication 42, containing the latest texts of the law (Appendices A & B). Repo;ts required by law should be reviewed and submitted to our Division within 30 days following the review (also see enclosed form letter of 1/29/76).

Please let me know if you have any questions in this matter.

EWH/mkr

Enclosure

cc: J.F. Davis, State Geologist A-P file (6) ,/-·

Sincerely yours,

EARL W. HART Office of the State Geologist RG# 462

' \ Reports Received from City of Pleasanton, 5/11/78 . (}

p..~-1> Consultant Site Dllte of· Report -1 • Judd Hull Romey Apts. 4/13/77

2. Judd Hull Civic Center additions 11123/77

3, Judd Hull Del Valle Plaza Apts. 1 /21 /76

4. Judd Hull Corrmerci a 1, West Angela St. 5/27/77

vs. App 11 ed So 11 Tract 3359 8/9/77 Meehan i cs

t Kaldveer & Assoc. Commercial & Citizen's 12/27 /77

(Did not receive this report; only received the Ka l dveer soil foundation report of 8/21/77).

7. Judd Hul 1 Duplex, 4487 Pleasanton Ave. 2/10/77

**8. Judd Hul 1 Triplex, 4566 Augustine St. 4/6/76

H<9, Judd Hull Triplex, 366 Rose Ave. 8/13/75

**10. Burkland & A~soc. Restaurant/office, 234 Main St. 8/5/75

*Report incomplete **Sites already under development when reports submitted to D.W. Carpenter

(who considered such reviews useless); see his letter of 11/22/77.

Reviewed

Yes - Adequate

Yes - Adequate

Yes - Adequate

Yes - Adequate

Yes - Adequate

Yes - Adequat;o

No

No

No

No

({:~U'lr @[? rPl!.rn~~~IRIU'@IM AREA CODE 415 846-3202 -:· 200 BERNAL AVENUE

May 8, 1978

Mr. Earl W. Jkrt Division of Mines and Geology 1416 Ninth Street, ttoo:u 1341 S~·oramento, CA. 95814

P.onr Mr. Hart:

P. 0. BOX 520 -;. PLEASANTON, CALIFORNIA 94566

Enclosed please find a set of geologic investigations of variou$ sites within Pleasanton relative to the "Pleasanton Fault". These reports were prepared pursuant to the Alquist•Priofo Special Studies Zonu Act. A number of i:he reports have been certified by Alao11::!a County's geologist, David Carpenter.

We hope this information will be of some value to you in your review of the potent!.al seismic hazard within and surrounding the corridor curr<>ntly coappe•:.c ~• i11cluding traces of the "Pleasanton F~c..1lt". If you have any further qu,,scions 1•l<>ase contact """''·

~~~o,,, ... Richard Glenn Planning Analyst

RG:mb

Enclosure-

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PlJBl.IC WORKS AGENCY COUNTY OF ALAMEDA

Mr. R>ibert J. Harris Director of Planning City of Pleasanton P. 0. Box 520 Pleasanton, CA 94566

Dear Mr. Harris:

399 Elmht11·st Street• HiOyward,CA IJ4544 • (115)8tn-6651

BUILDING INSPECTION DEPARTMENT

November 22, 1977

In accordance with your request, several recent geotechnical reports presented to the City of Pleasanton by applicants for building permits for sites within the Special Studies Zone, Pleasanton Fault System, have been reviewed. Reviews were made for three purposes. First, a determination was made as to which of the subject geotechnical reports should be rev:tewed for conformance with provisions of the Alquist-Priolo Act. Second, affected reports were reviewed for conformance with· d"" requirements of the Act. Third, all the data presented was reviewed for its effect upon the Civic Center Expansion project, City of Pleasanton.

The review process consisted of a careful study of the reports and a field inspection of the project sites.

All of the reports submitted are for projects subject to the current provisions of the Alquist-Priolo Act. However, three of the projec:t~ have been completed or are nearly complete and therefore, it--aoes·'not .. app-ear that a formal review of these reports for compliance with provisions of the Alquist-Priolo Act would serve any useful purpos7. The three completed or nearly completed projects are the building .conversion at 234 Main Street, and the apartment units at·-4566 Augustine Street and

1366 Rose Street. Data from these reports was considered during the evaluation of the Civic Center Expansion site.

The other four reports were reviewed for compliance with requirements of the Alquist-Priolo Act. Comn1ents are offered i.n the following paragraphs. In accordance with our discussions, charges which can be directly allocated to reviews of specific projects are listed following the commentaries.

1. Del Valle Plaza, Apartment Comple~:

Study prepared by Judd Hull and Associates dated January 1976. This site is at the margin of the Special Studies Zone and much of the property is outside the limits of the zone. The report provides geologic data sufficient to establish that the possibility is remote that a fault exists which affects the near-surface portfon of the Holocene alluvial sequence beneath the property. It is my pro-

( (

l1r. Robert J. Harris -2- Nov. 22, 1977

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fessional opinion that the report prepared by Judd Hull and Associates provides satisfactory compl~1l.IlcJi' with the requirements of the Alquist-Priolo Act~:-" Coat" iITf0cati~35·;·oa:-

2. Romey Apartments, 418 Rose Avenue:

Study prepared by Judd Hull and Associates dated April 1977. This study contains substantial data but the data is presented in such a way as to be in:::conclusive with respect to the presence or absence of a Holocene fault affecting ttiii- property. The illustrative cross section is drawn so as to nearly parallel the possible fault trace and the seismic refraction profiles are oriented at acute angles to the possible fault trace.

In view of their orientation, the effectiveness of the seismic refraction profiles in detecting the Pleasanton Fault, if present, should have been more thoroughly discussed. One of the profiles evidently represents a reinterpretation of previous data, the reason for the reinterpretation should have been explained.

Borings made on the project site are oriented roughly at right angles to the possible fault trace. However, no illustrative cross section or other. interpretation of these borings is presented.

In view of the above deficiencies, it is my professional opinion that this report in its present form <;)_o_~§I nJtt pry__yi\I~ ::l-~~-!s~a!'to:r::y_cornpl_~ance with the requirements of the Alquist-Priolo Act. Allo"ation of costs to date $70.00.

3. Commercial Project, West Angela Street:

Report prepared by Judd Hull and Associates dated May 1977. This report includes trenching and boring data adequate to demonstrate that the possibility is remote that a fault exists which affects the near-surface portion of the Holocene alluvial 1rnqucn<0.e beneath the site. It is my prof,~ssional opinion that the report prepared by Judd Hull and Associates provides satisfactory

~------..,...._.,. --.. compliance with the provisions of the Alquist-Priolo Act. Cost allocation $3.S.OO

4. Creeks Bend Subdivision, Tract 3359, Del Valle Parkway:

Report prepared by Applied Soil Mechanics Inc. and Burkland and Associates dated August 1977. This report presents on-site and off-site data adequate to demonstrate that the possibility is remote that a fault exists which affects the near-surface portion of the Holocene alluvial sequence beneath the site. It is my professional opinion that the report prepared by Applied Soil Mechanicn Inc. and Burkland and Associates provides satisfactory compliance with the provisions of the Alquist-Priolo Act. Costailo'caEioii- $51":sn--: ·· --

1be geologic studies which have been prepared for projects located in the vicinity of the Civic Center Expansion site have uncovered no evldence for the existence of the so-called Pleasanton Fault. Faults do exist in the hills north and south of the Livermore Valley, as for instance near the General Electric facility on Vallecitos Road1 but linking of these features to form a fault which traverses central Pleasanton cannot he supported by any data except a slight change in some water levels in the tleep subsurface. These water level change.a may not reflect faulting since the aquj_fer system beneath the Livermore Valley is exceedinely c0111plex and many of its cnmplexitfea are :rebt:ed to lateral as we1.l as vertical strata changes which refleet varied and shifting depositional erfvironmcnts.

• '' J J (

Mr. Robert J. Harris -3- Nov. 22, 1977

As noted in the geologic report prepared for Tract 3359, an air photo lineament exists which may be linked to the Verona Fault n.car the Ceneral Electric property. However, this lineament is located nearly 2000 feet southwest of the CiviC. Center expansion site.··

Geologic studies reviewed or prepared by the undersigned do not indicate that any undue hazard related to active faults exists at the City of Pleasanton Civic Center Expansion site. Therefore, in accordance with our conversations, the Waiver

* of Studies Form has been completed and is attached. The City of Pleasanton should fill out th.e section listing supporting d .. ta and include these when the waiver foi-m is sent to the State Geologist. For reference, a copy of the East County Government Center report is on file in the of fices of the California Division of Mines and Geology, Ferry Building, San Francisco. No extra copies of this report are available, but I would be pleased to lend the City of Pleasanton my file copy for reproduction whenever convenient to the City.

Total costs for this review are $461.63. Of this amount, $227.50 should be charged to reviews of individual private building projects as noted above as in previous correspondence. I have appreciated this opportunity to provide geologic services for the City of Pleasanton and would be pleased to do so again if desired by the City of Pleasanton.

DWC:dl

'ff Enc.

Very truly yours,

f)~ w.~~tA David w. Carpenter Alameda County Engineering

Geologist R.G. #248 C.E.G. #135

.<

GEOLOGIC AND SEISMIC HAZARDS J:NVESTIGATION

CREEKS TIEND SUIIDIVJ:SION 'l'RACT 3359

Pleasanton, California

AUGUST 1977

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File No. AS-0619-Jl August 9, 1977

Morrison Homes P.O. Box 23172 Pleas~nt Hill, California 94523

Attention: Mr. Dudley Frost

Subject: Proposed Creeks Bend Subdivision Tract 3359, Pleasanton, CA GEOLOGIC & SEISMIC HAZARDS INVEST'IGATION

Gentlemen:

Pursuant to your authorization, we have completed an investigation of Tract 3359 in Pleasanton, Alameda County, California.

The primary finding of this investigation is that there is no evidence for the Pleasanton Fault to cross the site. There are no geologic or seismic hazards at the site that would preclude the proposed construction, provided the recommendations of this report and those of the soil and/or design or structural engineers are implemented.

We were assisted in the preparation of this report by the firm of Burkland and Associates, Palo Alto, California.

It has been our pleasure to serve you.

Very truly yours,

APPLIED SOIL MECHANICS, INC.

Murray Levi.sh, Consultant Certified Engineering Geologist 194

Ben A. Patterson, Vice President Certified Engineering Geologist 594

ch

Copies: 6 to Addressee 2 to MacKay & Somps, Pleasant: Hill

,.

F~,1•$ No. A5-0619-Jl •·· .. August. 9, 1977

CONTENTS

GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION

INTRODUCTION Location and Description of Site Purpose and Scope Methods of Investigation Geologic Setting

INVESTIGATION PROCEDURES AND RESULTS

Literature and Map Review Aerial Photograph Interpretation Geologic Reconnaissance Review of Soil Data Assessment of Seismic Hazards

CONCLUSIONS

RECOMMENDATIONS

BIBLIOGRAPHY Publications, Reports and Maps Aerial Photographs and Radar Imagery

LIMITATIONS

APPENDIX - Logs of Borings from Gribaldo, Jones and Associates Report dated September 22, 1971

FIGURES

Figure l - Site Location Figure 2 - Site Plan Figure 3 - Regional Fault Locations Figure 4 - Local Fault Locations figure 5 - Section Along Arroyo Mocha Canal Fi~ure 6 - Log of Arroyo Del Valle Creek Profile

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1 4 4 5

8 l 3 14 l 6 17

21

23

24 27

29

2 3 7 9

12 l 5

.. File No. AS-0619-Jl l\ugust 9, 1977

GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION

I. INTRODUCTION

A. Location and Description of Site ------·-···-

Tract 3359 is located adjacent to and north of Arroyo de Valle

in Pleasanton, Alameda County, California (see Figure l, page 2).

The site consists of approximately 23 acres and is irregular in

shape. It is bounded on the north by Del Valle Parkway, on the

east by Lands of Valley Community Church, on the south by Arroyo

del Valle, and on the west by Hopyard Road. This boundary infor-

rnation was taken from a plan prepared for Morrison Homes of

California, at a scale of 1-inch equals 40 feet, dated May 1977,

by MacKay & Somps, Civil Engineers, Concord, California. This

map was reduced and used as a base for Figure 2 (page 3).

The site is relatively flat, with a slight slope towards the

southwest. Elevations range from a high of approximately 330

feet in the southeast corner to a low of approximately 301 feet

in the bottom of Arroyo del Valle near the southwestern corner of

the site. A levee has been constructed parallel to the creek along

the southern boundary of the site. Previously, this site had been

utilized for agricultural purposes. Vegetation consists of gross

and ~1eeds on the level portion of the site with a heavy growth of

shrubs and isolated trees along the banks of the creak.

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PRESUMED ~PICE~TER OF Jlr':H:'.: 1Sl8 EA.Rl'HQUAK!:' MAG+ 1.0..-0.s

f'RESU8ED b:PICEITT,ER OF

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t~sux::o F.I'> rcr.ITTE.R or OCT. B, 1Rf1!:> EH.RTllQUl\KE. tu.G. 6. $.-~0. 5

PRESW".ED El"lCEl'll'EEt or• .JUt..Y 1. 19l.l EARTHQlJl\lCE.

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{,S. 2} M~qn~tude of B~)~~ted ~~~thquaM;~~ ~ rig-ut<ei:i t.~s!de tl1e 2Q-;:{tlt1on:a .f.ndii:=&t.(' tJien1.,:.!lt'I!! r ot' ei:1rt;h!:luakee at tha s~ plac.:!, (Ill ~qu.:il to or til!Ilollller t)l4..'1 the 1;1nr. plotted.

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SCALE IN M1L£S

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Active and potentially active faults near the study area. Selected earthquakes, magnitude greatei: than 6.0, that occu::;-red p,;ior to 1934 have been incluced with notations, eat-thquukes less than magnitude 4. O ar-c o.>ni ttcd. D<0ta slightly modified, n1ainly from California Division of Mines and Geology Scisniic Safety Information (1972): Prov;.sional. fault nt<ip of Culifornia; and Preliminary earthquake epicenter m<.p of Cal~fon1ia, J,934-1971 (.June 30).

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--·- Site Floundclry

Arroyo del Valle

Borehole from GJ.11, Investigation (1971)

e Dag Sample Locations

location of profile along r- r Arroyo dcl Valle

'F'ile No.,A5-05l9-Jl August 9, 1977

Development plans call for the construction of one or two-story

residential structures on the site.

B. Purpose and Scope

A Special Studies Zones Map of the Dublin Quadrangle, Division

of Mines and Geology (llart, lg74), in which the site is located,

designates the site area as a Special Studies Zone.

The purposes of this investigation were to identify and evaluate

the geologic conditions and seismic haz~s at the site, with

particular emphasis on the possible presence of active or poten-

tially active faults. Recommendations are made for minimizing

the observed and potential seismic and geologic hazards.

C. Methods of Investigation

The following procedures were utilized in the investigation:

l. Research and review of relevant geotechnical,

geologic, soils and seismic maps and reports.

2. Interpretation of aerial photographs and radar

imagery of the site and its vicinity.

4 Aoolied soil Mr.cnanlr.s

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'·· .. File No. AS-0619-Jl August 9, 1977

3. Geologic reconnaissance of the site and its vicinity.

4. Geologic mapping of the exposures along Arroyo del

Valle.

The assessment of seismic hazards, conclusions and recommendations

are based on analysis of the data obtairied by these methods.

0. Geologic Setting ----~------

The site is located in Amador Valley, in the west central portion

of the east/west trending Livermore-San Ramon Valley system, in

the Hamilton-Diablo Mountain Range of Central California. Nine

teenth century maps of the area show Amador Valley to be covered

by a shallow lake. The lake was drained in the early 1900's by

deepening the channels of the local creeks. The valley is

presently drained through the Sunol Gap to the southwest by

Tassajara Creek, Arroyo Mocho, Arroyo del Valle and Arroyo de

la Laguna.

The portion of the valley west of the Southern Pacific Railroad

tracks was flooded during heavy rains in December 1955. The

creek channels have since been deepened and modified to prevent

possible future flooding.

The valley system is underlain bf Quaternary alluvial deposits_

thnt consist of varying mixtures of clays, silts, sands and

5

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gravels. These sediments are estimated to be in excess of 500

feet deep in the center of the major valleys. These deposits

are generally soft and unconsolidated, in the geologic sense of

those terms. This fact, coupled with the presenc~ of the perched

water tables common throughout the valley, makes the entire area

susceptible to various modes of seismically-induced ground failure.

The surrounding hills, from which the alluvial deposits were

derived through erosion and deposition, consist predominantly of

Tertiary sedimenary formations (flail, 1958; Helley, et al., 1972).

Three active right lateral fault systems are known to exist in

the Bay Area, including the San Andreas, Hayward and Calaveras

faults. There is another series of faults, trending roughly

northwest/southeast, to the east of the site. These faults have

not been fully investigated, their locations and nature of

activity are not precisely known, but they are generally considered

to be potentially active. These include the East and West Liver-

more, Mocha, Tesla, Carnegie and Patterson Pass Faults.

The Pleasanton and Parks Faults have been mapped beneath the

alluvium in the site vicinity. The location and nature of

activity and movement along these faults are uncertain and have

been the source of much controversy as development of the

Pleasanton area increases.

The approximate locations of these faults in relation to the

site are shown on Figure 3 {page 7).

6

APPiied Soil Mechanics ''"""'."='"•' ·~<.•

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4tigust 9, 1977

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-REGJONAL FAIJ.,LT LOCATIONS

TRACT 3359 Pleasanton California

LEGEND FAULT: Oashed where approximate

Dotted where concealed Bowen I Crippen (1951)

Brown & Lee (1971)

Cal. Div. Mines & Geology (1974)

Dept. of Water Resourcei (1963)

Ford (1969)

Gibson & Wollenberg (1968)

Radbruch (1968)

Burkland and Associates (1975a)

llerd (1975)

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7 Figure 3

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File No. A5-0619-Jl l\ugust 9, 1977

II. INVESTIGATION PROCEDURES AND RESULTS

A. Literature and Map Review

The most useful literature and maps pertinent to this study are

listed in Section V(A) BIBLIOGRAPHY. Most of the published

geologic data on this area is of a preliminary nature, based on

reconnaissance techniques and the extrapolation of data rather

than on thorough investigation.

The Pleasanton Fault has been mapped on and immediately west

of the site (Bowen and Crippen 1951, California Department of

WHter Resources (1967), Ford 1969, Gibson and Wollenberg 1958,

Radbruch 1968) (see Figure 4, page 9).

The nature of faulting, location and activity of this and the

Parks Fault to the west are uncertain. Both faults appears for

the first time in the literature on a regional map by Bowen and

Crippen (1951), who do not state on what basis these faults were

mapped. Several California Department of Water Resources publica

tions refer to the Pleasanton Fault (C.D.H.R. 1963, 1966, 1967).

Their locations of the Pleasanton Fault are predicated on a 20-

foot vertical differential in water levels in wells spaced a

minimum of 1200 feet apart. The differential occurs at a depth

of greater than 200 feet beneath the ground surface. There are

no corresponding offsets in upper water tables or aquifers. The

8

ADDlled son Mechanics ON~,,., .. ,, .... & 'L"

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File !lo. AS-0619-Jl • August 9, 1977

Scale 1':'24-;' !) 0 0 L o_ c ,l\ ~ _ _fJ:l._IL~I.-L 0 Cl\ T I 0 i·I 5

TRACT 3359 Pleasanton, California

LEGErHJ

Bowen & Crippen (1951)

--- De!pt. of Water Resources (1967)

Ford (1969)

--- Brown & Lee (1971)

County Investigation

Cal. Cliv. of Mines [, Geology (1973)

-···- Burkland and .~ssociatcs (1971' & 1974)

-------0---- Spl:'cial Stud·ies Zone

Air Photo Lineation

9

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File No. A5-0619-Jl August 9, 1977

same references report minor differences in water quality on

either side of the Southern Pacific Railroad tracks. lhese

differences were used to map the Parks Fault, the location and

activity of which is also disputed (Burkland and Associates

1974a, b, 1975a). Differences in water quality can be indicative

of fault zones, but they can also be due to other geologic struc-

tures or conditions such as facies changes within subsurface

materials, contacts between geologic units, etc.

,Jennings (1975) shows the Pleasanton Fault to be a "Quaternary

Fault," or one that has moved during the last 2 mi1lion years,

but not during historic time (the last 200 years). Brown and

Lee (1971) show only the Pleasanton Fault. The Pleasanton

Fault has been zoned by the California Division of

Mines and Geology under the provisions of the Alquist-Priolo

Special Studies Zones Act of 1972 {Hart, 1977).

Radbruch {1968) reports evidence of fault creep (slow continuous

movement along a fault) on the Pleasanton Fault near Highway 580

north of the site. The slight offsets of fences and other

structures shown therein can be attributed to other phenomena

that are known to occur In the Livermore Valley, such as

expansive soils.

Creep has also been rerorted on the Pleasanton Fault in the Camp

Parks area, north of the site (Gibson and Wollenberg 1968 and

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U. S. Coast and Geodetic Survey 1970). The evidence sited In

these references was found to lie based on inexact survey data and

erroneous calculations (Burkland and Associates 1975a).

Helley et al. (1972) show the different alluvial units in the

valley to be continuous across mapped traces of the Pleasanton

Fault. A geologically recent fault would have created character

istically linear offsets or truncated contacts.

Burkland and Associates has conducted numerous geotechnical

investigations since 1973 at proposed development sites within

5 miles to the north and south of the subject site (Burkland

and Associates 1973a, b, c, d, e, 1974a, b, 1975a, b, c, d).

These investigations included aerial photograph interpretation,

geologic reconnaissance, geophysical surveys, and exploratory

trenching. The trenches were, for the most part, oriented across

mapped traces of the Pleasanton Fault. None of the investigative

techniques employed produced any evidence for the existence of

nctive faulting along the mapped ''Pleasanton Fault Zone.''

Several traces of the Pleasanton Fault have been mapped as cross-

ing perpendicular to the Arroyo Macho Canal between Hopyard Road

and Santa Rita Road in Pleasanton. A log of the canal was made

(Burkland and Associates 1975a) and is reproduced as Figure 5

(page 12). The. lacustr!ne sediments present in the banks of the

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File no. AS-0619-J I

320

Continued

0

Dark Grey CLAY Tan Clayey SAND

NORTH FACE

& Not Well Exposed with Hardpan

1000

Tassajara Canal

Tan Clayey SANO

F111 ---------------

Tan Clayey SANO with L1monite Dark Grey CLAY 1----------,-~s~ta~i~n~s_,_ ______________ ~

oark Grey Sanqy CLAY, Expansive Cootiliued. r--~~~~~__:__· ~-·~~~~--J

2000 3000

~~~~~~~~~~~~-~~-----~~~~~~~~~~;_;;;~D~a~r~k~G;r;e~y~S~a~n~dy~C~LA~Y~,~E~x~p~a~ns~1~·v~e~==================~~~~~~==~==============~~~==~'. Dark Grey Sandy CLAY r1 ,,_,.<!:' ~Pf

Tan SAND, Finely Dark Grey CLAY__..-,,_, Sa mp 1 e Ta keri for Radiocarbon Da t; ng ~ t- v

Continued

7000

4000

S.P.R.R.

Tan Clayey SAHD

Dark Grey Sandy CLAY, Expansive

•

5000

Santa Rita Rd.

EAST

Riprap

'-S'-. Concrete Cascades

8000

340

330

320

.~..., ••

VICINITY MAP {no scale)

...

~ SITE

6000

YA LLEY M EUORIAL HOSPlT AL

(B 8A 197:5)

7001)

Vertical Scale: 1"=10'

Horizontal Seale: 1 "=250'

SECTION ALONG ARROYO MOCHO CANAL (From Burkland & Associates, 1975a)

TRACT 3359 •

Pleasanton, California

..-· w ' -

.• F~~ e No. AS-0519-Jl August 9, 1977

.•

canal are nearly horizontal and show no vertical or lateral

offsets. It was concluded that there is no evidence for the

existence of an active fault in that area, which is located

approximately 1.3 miles north of the site. The location of the

canal in relation to the site is also shown on Figure 5.

B. Aerial Photograph Interpretation

A wide variety of aerial photographs and radar imagery of the

site and its vicinity were utilized in this investigation. They

are listed in Section V(B) BIBLIOGRAP11Y. The photographs and

imagery were examined for the presence of lineations and other

topographic features characteristic of active fault zones. No

such features were seen on the site or in the immediate vicinity.

Three lineations were seen in the area, the nearest about 900

feet east of the site. No lineation was seen in the mapped

position of the Pleasanton Fault on the site. No topographic

features characteristic of active fault zones were seen along the

lineations. All the lineations cross, but do not offset, irregular

contacts between different types of surficial materials.

A line of sand lenses, apparently the shoreline of an old lake,

can be traced from about three miles north of the site for more

than a mile to the west. The relic shoreline, wl1ich runs per

pendicular to some of the postulated locations of the Pleasanton

Fault, is not offset, indicating that the area has not been

subject to surface faulting in geologically recent times.

l 3

,. l·j

' I ,, ,, ii' :i /( ,. !i I I I

i I I Ii ,, I

1:· I ' I

I: Ii I/ I·

- , ~:· .


c. Geologic Reconnaissance -----···--------

The site is vacant and located in a developed area. Surface

features which might have been examined for evidence of active

faulting or other geologic and seismic hazards have been

obliterated by past development activities.

Pavements and structures in the areas where the Pleasanton Fault

had been mapped were carefully inspected for signs of fault creep.

but none were found.

The nearest undeveloped area where the Pleasanton Fault has been

mapped is in the hills, about 1/2-mile south of the site. Although

that area was closely examined for topographic or other evidence

of active faulting, none was found. In the summer of 1976, the

County of Alameda investigated a site south of Tract 3359 through

which the Pleasanton Fault was mapped. Trenching in bedrock on

that site; along with seismic traverses, failed to uncover any

evidence for the existence of the Pleasanton Fault (D. Carpenter,

oral communication 1976).

The banks of Arroyo del Valle adjacent to the site were geo

logically mapped. The banks locally attain a height of approxi

mately 28 feet. A log of the exposed materials is graphically

depicted in Figure 6 (page 15). The location of the Arroyo

in relation to the site is shown on Figure 2 (page 3).

14

APnlie~ Soll Mec/lanlcs ... , ... ,,~~,.,,, .. ,,."

' 'i! ,. , I

' '• ,, I

:J

i I

I )

,j - ~

1! ! I .i I l

l I I i

< < - - .. ~. J~ ....... ..J.- \,..I

340

330 A Brush

/ , , /

320

Feet 600 700 800

340

330 c / /

320

Feet 1200 1300 1400

levee ( fi 11 ) EAST

340 Concrete Debris (covered)

B 330 B

_,,,,..,...._,..._...,, , /

F ;;-- ~ r / ..... ./ ./

320 Concrete Embankment (covered)

Feet 1800 !900 2000

levee (fill )

(covered) A / / /

/ / F

900

levee ( fil 1 )

E

/ / / / , / /

F

1500

LEGEND

0 light Brown, fine Sandy SILT

~ light Brown, Gravelly SILT

@] Medium Brown, fine Silty ~AND

@]

[I]

0

c

!000

1600

Grey Silty GRAVEL

Grey Sandy GRAVEL

Grey, coarse River GRAVEL

See Figure 2 for location

B

/

B

/ ,

I

II 00

n 0 ::>

E ~ B ,.. ~

::> c: <I> a. y

1200

:> Concrete Embankment c:

<I> Cl.

,,. / ./ / / , / / ;,.,' Outfall

1700 1800

LOG OF ARROYO DEL VALLE CREEK PROFILE

Troct 3359 Pleasanton, California

Figure 6

I

,,

... 4:

..... '!',_~ •


Layers of alluvial soil, typical of those found in lake deposits,

are exposed. They consist of clayey sands and silts intermixed

with gravels and inclined slightly to the east. The surface

materials are granular and apparently not expansive. Groundwater

was not seen seeping from the banks of the creek. No evidence

for the existence of active faulting was seen.

D. Review of Soil Data

A report dealing with the soils of the.site was prepared by

Gribaldo, Jones and Associates (1971) and was reviewed for this

investigation. Eleven boreholes were excavated. The locations

of these boreholes are shown on Figure 2 (page 3).

lhe logs have been reproduced and are included in the Appendix.

No groundwater was encountered to the depths explored (maximum of

20 feet). Correlations of the logs indicate that none of the

sedimentary horizons have been vertically offset due to faulting.

Various horizons could be followed over the entire site.

Descriptions shown on the logs indicate that fine sands exist

beneath the site. These sands appear to be discontinuous and

confined between clayey silts. No blow count data nor gradation

curves for the sand deposits were presented in the report.

16

j

--.....-.-.--·---<\o"?.'

.• .

File No. AS-0619-Jl •August 9, 1977

E. Assessment of Seismic Hazards

The nature of soil and groundwater conditions in Amador Valley

and the presence of nearby active faults, make it particularly

vulnerable to earthquake effects. The earliest report of an

earthquake in the valley dates from July 3, 1861. That earth

quake had an estimated magnitude of 6 .. 6 and its apparent epicenter

was in San Ramon Valley. The ground was reported to have ruptured

for a distance of about 8 miles, from the town of San Ramon to

Walnut Creek. Ground shaking was so int~nse in the Livermore

area that people were reportedly thrown off their feet (Trask, 1864}.

Following the earthquake of April 18, 1go6, there were reports of

ground failures in the Amador Valley and the Livermore area.

Banks are reported to have collapsed along Tassajara Creek.

Relatively light structural damage was reported in and around

Pleasanton, however. During exploratory trenching, in 1970, at a

site west of the Southern Pacific Railroad tracks, remnants of

sand-filled lurch cracks were seen. These cracks probably

resulted from the 1861 or 1906 earthquakes. The earthqu.ake of

October 1. 1969, which was centered near Santa Rosa and had a

magnitude of 5.7, reported)Y caused the collapse of open utility

trenches in Pleasanton.

The site could be affected by an earthquake with its epicenter

on any of the active faults in the Bay Area. The known active

17

I '

I i l ' i '

Ii "

• ••

•.

'file No. AS-0619-Jl August 9, 1977

faults in the Bay Area and their nearest locations in relation

to the site are:

Approximate Location in Nature of

Fault Relation to Site Movement

San Andreas 25.0 miles west right lateral

Concord 20.0 miles north right lateral

Hayward 1 0. l miles west right lateral

Las Positas 3.5 mil es south left lateral

Calaveras 2. 1 miles west right lateral

The series of faults to the east of the site (see Figure 3, pa.ge 7)

has not.been fully investigated. Their existence, locations, and

nature of activity have not been demonstrated, but they are con

sidered potentially active until proven otherwise.

It must be assumed that movement along one or more of the Bay

Area faults will result in a moderate or major earthquake during

the lifetime of any construction on this site. In the event of

an earthquake, seismic risk to a structure will depend upon the

distance of the structure from the epicenter and source fault,

the character of the earthquake, the geologic, groundwater and

soil conditions underlying the structure and its immediate

vicinity and the nature of the contruction.

Ground rupture tends to occur along lines of previous faulting.

There is no evidence of faulting at the site, therefore, the

potential for ground rupture is considered to be low.

18

.• ' '

File Ho. AS-0619-Jl August 9, 1977

Liquefaction can occur in certain types of saturated soils during

earthquake shaking. These soils become "quick" and unable to bear

the weight of overlying soils and structures. Based on the Logs

of Borings from the Gribaldo, Jones and Associates report dated

September 22, 1971, it is our opinion that the potential for

liquefaction to occur at the site is considered to be moderate.

Lateral spreading can occur in areas susceptible to liquefaction,

especially where open faces exist. The potential for lateral

spreading to occur is dependent on the liquefaction potential

and, therefore, it ts rated moderate. If no groundwater is.

present, however, as shown on the Logs of Borings, ths liquefac-

tion and the lateral spreading potential should be downgraded to

low. The potential for slope failures to occur along tbe creek

banks is considered to be moderate to high.

Lurch cracking is the formation, usually temporary, of all types

and sizes of fissures in the ground due to ground motion during an

earthquake. Sand boils, mud volcanoes, and water gushers often

accompany lurch cracking, as groundwater is forced toward the

surface. The potential for lurch cracking at the site is con~

sidered to be moderate adjacent to the creek and low elsewhere

on the site.

Local subsidence can occur during an earthquake when shaking

drives water out of saturated soils causing them to become more

19


compact. The potential for local subsidence at the site is

considered to be low.

Structural damage due to ground vibration is caused by the trans

mission of earthquake vibrations from the ground into the structure.

The var1ables which determine the extent of damage are: the

characteristics of the underlying earth materials, the design of

the structure, the quality of materials and workmanship used in

construction, the location and magnitude of the earthquake, and

the duration and intensity of shaking. The most destructive

effects of earthquakes are usually seen where the ground is

unstable and structures are poorly designed and constructed.

Preliminary estimates of the ground response characteristics of

the site indicate that high peak bedrock accelerations can be

anticipated during a moderate earthquake centered on the Calaveras

Fault, or a major earthquak~ centered on the Hayward Fault or

San Andreas Fault. The duration of shaking and frequency com

ponents of the vibrational waves will depend upon the magnitude

and location of the earthquake. Structures should be designed

to accommodate earthquake vibrations, and if quality construction

criteria are met, structural damage can be minimized.

20

I

1'

' I I·

r f

I 1,

. • . '

File No. A5-0619-Jl August9, 1977

I I I. CONCLUSIONS

The following conclusions are based upon data obtained and

analyzed during the investigation of the subject site.

l. There is no evidence for the existence of an active

fault at the site. The potential for ground rupture

to occur is considered to be low.

2. Nci evidence was found to substantiate previously

reported locations of the Pleasanton Fault in the

vicinity of the site.

3. No evidence of fault creep was seen in the vicinity

of the site.

4. The potentials for the seismic effects of lique

faction, lateral spreading, lurch cracking and local

subsidence of soils are considered to be moderate if

groundwater is present and low if groundwater is

absent at this site.

5. The potential for localized slope failures to occur along

the Arroyo del Valle is considered to be moderate

to high.

6. A moderate to major earthquake on the Calaveras Fault

or a major earthquake on the Hayward, Concord or

21

••

I I [

• ..

file No. A5-06lg-Jl August 9, l g77

San Andreas Faults could produce severe ground

shaking at this site.

7. There are no geologic or seismic hazards at the site

that would preclude the proposed construction, pro

vided the recommendations of this report and those

of the architect and/or design or structural engineer

are implemented.

22

.. File No. A5-0619-Jl August 9, 1977

IV. RECOMMENDATIONS

The following recommendations should be implemented to mini~ize

the geologic and seismic hazards present at the site.

1. The architect and/or structural or design engineer

planning the improvements should be aware of the

potential seismic ground shaking characteristics of the

site in the design and construction specifications for

all structures planned for this site. The 1976 or

later edition of the Uniform Building Code should be

consulted in the design of all improvements.

2. Further evaluations should be made to assess the soil

slope stability along the creek. Based on the findings

of this recommended evaluation, setback distances should

be established in the proximity of the creek bank, as

needed for any planned structures.

23 Annlled SOil MBChanlcs

• I l •

• . '


V. BIBLIOGRAPHY

A. Publications, Reports and Maps

1. Alameda County Planning Department, 1975, SEISMIC SAFETY ELEMENT.

2. Bowen, 0. E. and R. A. Crippen, 1951, GEOLOGIC GUIDEBOOK OF THE SAN FRANCISCO BAY COUNTIES, California Division of Mines and Geology Bulletin 154 .

3. Brown, R. D., Jr., and W. H. K. Lee, 1971, ACTIVE FAULTS AND PRELIMINARY EARTHQUAKE EPICENTERS (1969-70), IN THE SOUTHERN PART OF THE SAN FRANCISCO BAY REGION, U. S. Geological Survey, Basic Data Contribution 30.

4. Burkland and Associates, 1973a, GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION, MISSION PARK SCHOOL SITE, PLEASANTON, CALIFORNIA.

5.

6.

7.

, 1973b, GEOLOGIC AND SEISMIC HAZARDS ~I ~N V~E~S~T~I~G~A=T~I o=N~,~C~O~N~C~O R~D~S TR E ET ELEMENTARY SCH 0 0 L S I TE , PLEASANTON, CALIFORNIA.

, 1973c, GEOLOGIC AND SEISMIC HAZARDS "'It'""lV.,..,E'""s=T"'IG""A'""Tc;-I""ON"'",----"D..,.I""ST=R'""I"'C=T ADMINISTRATION BUILDING, PLEASANTON; CALIFORNIA.

, 1973d, ALAMEDA COUNTY TRACT NO. 3364, "'"p .-L E""A,,..,S'"'A'""""N'""'T"'"O""'"N-, ....,C"'A"L-.I'""F""O""'R-;-;-N "I A.-.

8. , 1973e, GEOLOGIC AND SEISMIC HAZARDS lNVESTlGATION, DUBLIN BOULEVARD SCHOOL SITE, DUBLIN, CALIFORNIA.

9. , 1974a, PRELIMINARY GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION, VALLEY MEMORIAL HOSPITAL, PLEASANTON, CALIFORNIA.

10. , 1974b, SUPPLEMENTARY REPORT, GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION, VALLEY MEMORIAL HOSPITAL, PLEASANTON, CALIFORNIA. .

11. , 1975a, SUPPLEMENT 2 TO THE GEOLOGIC ANO SEISMIC HAZARDS INVESTIGATION, VALLEY MEMORIAL HOSPITAL, PLEASANTON, CALIFORNIA.

24

l I I

. . File No. A5-06lg-J1 August g, ig77

12. Burkland and Associates, 1975b, GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION, TRACT 3606, PLEASANTON, CALIFORNIA.

13. , 1975c, GEOLOGIC ANO SEISMIC HAZARDS INVESTIGATION, PROPOSED U. S. MAIN POST OFFICE SITE, PLEASANTON, CALIFORNIA.

14. , 1975d, GEOLOGIC AHO SEISMIC HAZARDS INVESTIGATION, PROPOSED RESTAURANT AND OFFICE REMODELING SITE FOR MR, VIC LUND, PLEASANTON, CALIFORNIA.

15. . , 1976, GEOLOGIC ANO SEISMIC HAZARDS INVESTIGATION, PROPOSED ADDITION TO VALLEY MEMORIAL HOSPITAL, LIVERMORE, CALIFORNIA.

16. California Department of Water Resources, 1963, ALAMEDA COUNTY INVESTIGATION, California Water Resources Board Bulletin 13.

l 7.

18.

, 1966, LIVERMORE A N 0 s u N O"'L----,,V"'A.-L "'L ... E v""s"""",--..E"'V"'"A..-L"'"U A""T'""I,..,O"N,_..,.0-,.F_W.,.A"""T"'E""R....-.<-R E s 0 u R c Es ' B u 1 l e t i n 118-2, Appendix A, Geology.

~~~~~~~~~--~~~~--~· ] g57, BAY DISTRICT OFFICIAL PROJECTIONS, unpublished.

19. California Division of Mines and Geology, 1974, SPECIAL STUDIES ZONES MAPS, DUBLIN.QUADRANGLE.

20. Ford, Robert S., 1969, GROUNDWATER GEOLOGY OF LIVERMORE VALLEY - A SATELLITE URBAN AREA, Urban Environmental Geology in the San Francisco Bay Region, Association of Engineering Geologists, Special Publication.

21. Gibson, W. M. and H. A. Wollenberg, 1968, INVESTIGATIONS FOR GROUND STABILITY IN THE VICINITY OF THE CALAVERAS FAULT, LIVERMORE AND AMADOR VALLEYS, ALAMEDA COUNTY, CALIFORNIA, Geological Society of America, Volume 79.

22. Gribaldo, Jones and Associates, 1971, SOURH ORLOFF PROJECT, PLEASANTON, CALIFORNIA, SOIL AND GEOLOGIC INVESTIGATION.

23. Hall, C. A., Jr., 1958, GEOLOGY ANO PALEONTOLOGY OF THE PLEASANTON AREA, ALAMEDA ANO CONTRA COSTA COUNTIES, CALIFORNIA, University of California Puhl. in Geol. Sci., Vol. 34, No. 1.

24. Hart, E.W., 1977, FAULT HAZARD ZONES IN CALIFORNIA, California Division of Mines and Geology, Special Publication 42, revised edition.

25

• File No. A5-06l9-Jl August 9, 1977

25. Helley, E. J., K. R. Lajoie and O. B. Burke, 1972, GEOLOGIC MAP OF LATE CENOZOIC DEPOSITS, ALAMEDA COUNTY, CALIFORNIA, U. S. Geological Survey, Basic Data Contribution 48.

26. Herd, D. G., 1975, LAS POSITAS FAULT, AN ACTIVE NORTHEASTTRENDING LEFT-LATERAL. FAULT IN EASTERN ALAMEDA COUNTY, CALIFORNIA, Geol. Soc. Amer. Abstracts Vol. 7. No. 7.

27. Huey, A. S., 194B, GEOLOGY OF THE TESLA QUADRANGLE, California Division of Mines and Geology Bulletin 140.

28. Jennings, C. W., 1975, FAULT MAP OF CALIFORNIA, California Division of Mines and Geology, Geologic Data Map Serfes, Map 1. .

29. Radbruch, D. H., 1968, HEW EVIDENCE OF HISTORICAL FAULT ACTIVITY IN ALAMEDA, CONTRA COSTA AND SANTA CLARA COUNTIES, CALIFORNIA, Stanford University Publications, Geological Science, Vol. XI.

30. Trask, J. B., 1864, EARTHQUAKES IN CALIFORNIA FROM 1800 TO 1864, Proceedings of the California Academy bf Natural Sciences, Vol. 3.

31. U. S. Coast and Geodetic Survey, 1970, STUDY OF EARTH MOVEMENT DETERMINED BY TRIANGULATION CAMP PARKS VICINITY OF PLEASANTON, CALIFORNIA, Supplement No. l.

26

f I

I I

. " ..


B. Aerial Photographs and Radar Imagery

Date

10/13/49

5/16/57

3/7/58

1965

1965

9/16/68

3/15/70

4/70

8/13/70

9/2/70

1970

Source Type and Scale

U. S. Geological Black & White Survey Vertical

Sunderland

Pacific Resources

Goodyear

Goodyear

Pacific Resources

Pacific Resources

Pacific Resources

Pacific Resources

Pacific Resources

U. S. Geological Survey

27

1:24,000

Black & White Vertical l : 12.000

Black & White Vertical 1:36,000

Side Looking Radar, Approx. 1:250,000

Si.de Looking Radar, Approx. l :36,000

Infrared Oblique

Infrared Oblique Scale Distorted

Black & White Vertical 1"~2mi.

Black & ~/hite Vertical l :36,000

Black & V/hite Vertical 1:48,000

Black & V/hite Vertical 1:125,000

Picture Nos.

GS-JL 2-21 thru 2-29

AV-253-23-36 thru 41 AV-253-24-35 thru 40 AV-253-25-38-thru 43

SF Area 3-98 thrll 1010 SF Area 3-61 & 62

Mosaic of Bay Area

North/south strip along Sunol Ridge

Ala-E-294

Ala-E-346 Ala-E-342

Mosaic

AV-965-12-24 thru 26

AV-965-11-23 thru 25

Mosaic

• ~ile No. A5-0619-Jl August 9, 1977

Date Source

4/12/71 ·Pacific Resour-ces

12/17/71 Pacific Resources

6/72 NASA

11/72 Paci fie Resources

28

Type and Scale Picture Nos.

Black & White AV-994-02-18 thru 20 Vertical AV-004-02-17 thru 19 1:2,000

Black & White Special Flight Infrared at Low Sun Angle Ver-ti cal 1:6,000 1:12,000 1:42,000

False Color Flight 72-105 Infrared Film 1824 & 1825 1:120,000

false Color Special Photography Infrared Vertical 1:12,000

.. .• •.

APPENDIX

Logs of Borings from Gribaldo, Jones and Associates Report dated September 22, 1971

'

~·· •

-• II

• • -


NOTE: Taken from Gribaldo, Jones & Associates Report 9/22/71

Boring No. 1

O 'n, ' ·1 Brm·m Clayey to Sanely SILT, · . , , '. damp to moist, stiff (:ML) ·

. .

•

. 10 . 1-3

•

•

·1s · .16. 1-4

. Brown Clayey SAI'-JD, moist to wet, firm (SC)

Boring Terminated at 16 feet

.

.

Figure No. 2 - Log of Best Borinr, No. 1

""'

.

93.3 15.6

101.5 19.9

113.0 16.4

19.9

I

.

• •yf.ie• No. AS-0619-Jl Pi.ugust 9, 1977


Ci:Pr ft $4.'.'i"l..E LOG 8 ~~holl re:atlPJION

'·' NO. !JX:ATIONi ~~·:!!·~ !",!"Ef "' !-t.'rf~e 8h:i,rtt/tl

............ 0 . Boring No. 2 . , ,

Brown Clayey to sandy SILT, dry , , .. • , v loose, first 12 inches (ML) •' , . . , , ,

:~J~i\·f ·~,\)i . . 2-1 Brown Silty SAND, moist, firm(SM) . .

, ~

• 5 . , , '. Brown Clayey SILT, moist, stiff

'' , .

(ML) , • . , •' ••

, , • . , , , , Brown Clayey SAND, moist, soft , , , , , , (SC) ' .

i , ,.

2-2 ; ,. , , , . . , , , , , , ·10 . , , , , , , Brown Clayey SILT, moist, soft . . , ,

c (ML) , , , . . , ,

2-3 1:J#~!~li1 Brown Silty SAND, moist, finn(SM) . .

·14· Boring Terminated at 14 feet . •

. .

. •

. . .

. . • . . •

. . . . • . .

. .

. .

. .

. .

. .

Figure No. 3 - Log of Test Boring No. 2

IN~Pt...-CE

••• f/.01!.TURE

DtNSIT"f CO"Ttrff pl!:.I . %~ .. t

I

95.S 16.9

.

111.6 16.8

.

111.5 16.8

I

. ·riie' No. AS-0619-Jl August 9, 1977 NOTE· Taken from Gribaldo, Jones & Associates Report 9/22/71

""''" $~,ill'LE: COG & ~,.0.•D'1 ~:SCRIPllO~

'" NO. l(ICAflO~ Oln11~

t~E1 O>

S..Mr,.~ &i°"'~H

0 Boring No. 3 . . x,. '

:1 Brown Clayey to Sandy SILT, dry

• • '-, , loose first 12 inches , . . , , ,

' . .

3-1:1 Brown Silty SAND, moist, firm (SM) . . 5 .

. • .· ,, , . .. Brown Clayey SILT, wet, soft(ML) . . , , , , , , . • / ,

' , , . •

~ . , ,

·10 , ..

• , , , , , . • , , , ,' '

·;12 . , .

Boring Terminated at 12 feet . . . . . •

.

• . • . . . • •

· . . . . • . . . . . . . .

. . .

. . .

Figure .No. 4 - Log of Test Boring No. 3

IN•.PLAC(

.. .. 11.':V1$f1,J"RC Dli:N!1T·1' C.OfH£HT

Pet. ,.I;!°'" ""'·

.

99.2 11.5

-.

t I

,, • F:ile No. AS-0619-Jl •.August 9, 1977

NOTE: . d & A R 9/22/71 Taken from Gribal o Jones ssociates eport

• 0 ·1 . 4-1 .

. ..

5 .

4-2

·10 . 4-3

J.2 •

•

•

.

. . .

P.orinR No. 4 Brown Clayey SILT, dry, loose to first foot (ML)

Brown Sandy SILT, damp, stiff (tU.)

Brown Silty SAND, moist, firm(SH)


.


ORY

pe.f.

91.l

102.7

106.0

.

MOtS1U'Rt

~tEta

"la. drt ~I.

17.4

19.6

19.9

I I

•• •FB,e:· No. A5-0619-Jl August 9, 1977

NOTE: Taken from Gribaldo, Jones & Associates Report 9/22/71 '

""' O!H511'1 p.d.f.

M0'5fUA!'. eoNT(l'IT

%Gt-r 1111,

0 ,,_I __ ..,._,...,.~,-.--t-B;;......o.;;.r_i..;.n;o.,g:.....:.N~o-.__.5'"'--~---------~:.--~~---~ '6l',' Bro•·m Sandy SILT, dry, loose first

•' .

5 . I

• ''•

•

•

' . •

'·15 . •

'20 .

, ' foot (ML)

, , , , . , , , . , . ,

/ .

, ,

, . , ' ' , , , ,

,; "'" ~ . ,

Brown Sandy SILT with Clay, moist, stiff (ML)

Brown Clayey SILT, moist to wet, soft (:HL)

Brown. Silty SAND to Clean SAND moist, firm (SM-SP)

'

Brown Clayey SILT, wet, soft (ML)


Figure No. 6 ~ Log of Test Boring No. 5

'

'

'

'

r

'

•

'File No. AS-0619-Jl •August 9, 1977 NOTE: Taken from Gribaldo, Jones & .Associates Report 9/22/71

'

~.P'!"tt SAMPL.E >OG ~ ~r!•Ol10ll O..-s<:R1 PT IOH

'" ""· L0::4.1"101V ~~ll~ICI'~·

n::Ef 0,

Si\:JPLE ~OwJ/fl

o . Boring No. 6 . , ,. I . , Brown Clayey SILT, dry, loose , . • , first foot (ML) , ~,1 , , . .

fj . ,,

6-1 • •

• • Gray Clean fine SAND, damp,firm ':

'

(SP) • 5 . ! . . '

6-2 , 'u::I ' •q • . ,,. .

Gray Gravelly SAND Sanely J. ~ <l· to . • "Q'o(, GHAVEL, moist, dense (SW-l'W) l',a • () .l ' . "" . •' . • l>c:i·£r{l "J • () :.10. 0 ··Q 04CJ,.,·,, ., '

'• • ,\)'Ve Q j; 0

.12. o~: t

Boring Terminated at 12 feet . . . •

. .

. •

• . . • . • . .

' . . .. .

. .

. .

. .

. .

. . ' . .

'


1:1.1~ ~I.ACE;

n•• M01s1'u~·a::

OE.NSITY tO~l'EliT

~l!.f. 'o/t> Cr'f wt.

90.0 10.3·

95.5 7.0

'

'

I

I ,,

I f

I I

... ;"

'

~ File No. AS-0619-Jl 1August 9, 1977


S.'-"•'?Lt 1,.0(I. 9i .,_,tltQ'•Oit Clt$C:FttPTION

'" hO. ~-n0r4 R1:1~1'hnH OF

SA~f B:ootVl1

MY

DEkSllY · P:c.l

'

t.'01$TUR£

COOTf:Hf %ut •f-

Boring No. 7 0·1--~-'f;,r-r:-r?-~~,-~~..,.:;:..-_,...~~_,...~~,~~~..-_,...~~~~.f-~~--11~..-~-5

' , ' · Brown Clayey SILT, dry, loose

7-1

5 .

7-2

·10.

7-3

1.5 .

' ,', f1.,..et fnot fML'

;....;.' .. ,, , , . ', , , , , • . ,

Brown Silty SAND, damp to moist, firm (SM)

Brown Clayey SILT. moist, stiff (ML)



91.6

114.9 15.5

113.2 13.5

'

'

, I

'

. ' '.~ ' . F:i.li No. A5-0619-Jl

'·August 9, 1977


,.,..,.f:Jl..A(:(

'::i...""Ptl'i S4'-l~t LOG ~ :oo.-....11ot1Q11 l)S"....SC~IPllO~

'" flO. IJX..'ftON iil~~·i.ri:ine•. DOY . t.!01STUfff: o• D!MSIT'f (O:llTEtn f'Eff $:t.Mi11..£ eic·.i1/ft

·~· %11"1 wfr.

.

I I Boring No. 8 I 0 ..

~t?A -Brown Silty CLAY, dry, loose . . first foot (MLl___

95.6 7.2 . . Brown Silty SAND, damp, firm(SH) . .

• • 8-2 Sample· .. .

Dist urbed • 5·

100.4 13.1 . • . .

8-4 ,

I,, Samph , , . . . ~ Clayey SILT, moist, stiff Dist cir bed , Brown c' , ,, (HL) . . ,

-~

·10. [\ •\):

8-5 !l'~"< Gray Gravelly SAND, damp, dense 108.7 8.7 . . !"1l o· (SW) E)• 0 ~:'..... . .

ii . . Light Brown Silty SAND, damp, .

firm (SM) . . ·15 •

Boring Terminated at 15 feet . . . . . . .

. .

. . I ' . .

. . • . . . . . . . . . .

. . .


' " ,. :t:i:le No. AS-0619-Jl

jAugust 9, 1977

' . NOTE: Taken from Gribaldo, Jones & Associates Report 9/22/71

f.r:l•Pl.4.C.£

:J.P''°" $~".l?I.( l.OG 6. .:>¢tlf~tJ-Cioll OEStR1PT10tl

t~ '"'- 1.DC\\"ION ~O:~fa-:~• ORY ~1$TU~E:

F"t.t:r 0, OtN'Sl'\""t' C.O:otT!tli

$.1.M;;>t,£ B;i:-,.!/fl Pf: t. 6,b. !Jrt wi.

-'

I I Boring No. 9 I I . 0 •" • I ' . 'j . ·1 ; . Brown Clayey to Sandy SILT, dry

' ., loose first foot · . . i • .

:1 ,_,,ilil Brown Silty SAl.'ID, moist, firm(SM) 98.6 15.2 . .

. . 5 :1 •

• ;

~1 . ., '. , Brm·m clayey SILT, wet, soft(MI,) • , , .

] -· , 9-2 '. ! ...

,• _,, 103.6 18.7 . r·-:- --. ! -l ~;fl':_;_ Light Brown Sandy SILT, 1noist, . •j r .·-· __ , :){ ;:; ·:1 stiff (ML)

·10· ,,yL-. . 9. 3 . ,\:".if :'J\i - . ,,.-:• q:;: 110.2 18.4 ·12· .tlorl.ng r ermJ.na tc<1 ai: 1.L i.:eei: . . .

:1 .

•

• • . . .

. . - . . . . .

. -• .

. . . •

. .

. .

. . .

. ·I Figure No. 10 .,. Log of Test Boring No. 9

A ril~ No. AS-0619-Jl '• f>ugust 9, 1977


'

'

'

'" n::~r

•

•

• s . '

' ,, •

• ., . .10.

'

.

·15.

• .. . •

fto. LO"'"..A. flO'.'i ;tl'~•f.~ OF

5Jlr.M"'!; 9:°0 .. J.111

• /I 1." .. j ,/ , L :1

, L'

/ / , , , / , ,

' , , , , , , '

,, , 'I , '·' .. , f ... · , / , ,

'· ' ,

D'""...SCiUF>llON

Brown Silty SAND, moist, firm(SM)

Brown Clayey SILT, wet, soft(ML)


'


INr PLl..C.~

OA'V "-'0~$TIJ1ti:

O~N!llT'f CC>~T!;Kf

PC.' % City wt.

'

'

• , ""'-' fi.1e No. AS-0619-Jl '<!"· 1Augi.lst 9, 1977

'(


·.

~t:tr .

L.O!J, &

IJX~flON

OF $4.Mr>l.!

t>E:SC>l:IPTION

"'" ~c.r.

t.10tSTUll:E. ;

C.O:~TENl'

%drr ... t. i

--i~--:l·~-:,·~--:1-B_o_r-in-.g~N~o.~l·l-~~--~~--~---'l~~~-i-~--t.

. o·,--FTIJit-!, --j Brm·m cr.uyey S1L1', ili:TTUoi;e

. . ~~ Brown Sandy SILT, damp, stiff (ML)

. :1 tj? c~t~:j::.:i

. i 1-1 Yj:·':. ::: 1 • • '--~ .. :!-. ':.:

~.I,-":~~: :~_i .s ... , .. ·.··i . ·I :; ·,~ :': ~~1r-· -.. t ..... i , ,

I , , • .··- ii I

i 11-2 ' ·1 Bro<,-rn Clayey SILT, moist, (Jtiff

{ML)

I•. .. 7 ' ,,.

, ' ·- . ~""""""*''--+-----------Bro'vn Silty S'AND, inoist, firm (:ML)

.

.

Boring Terminated at 14 feet • ·1

: :i • . • . . . . . . .

.. . .

.

Figure No. 12 - Log of 'fest Boring No. 11

87, l; 8.7

103.D 18.5

112.5 16.1

.

&t:t# 7/;e7/77 - California€¦ · 9/8/1977 · °'m"ate of califor:nia.~thf resources agf:ncy department of conservation etsmund 0. bl{own jfl:., g1;1ve,nor division of mines and

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