DIVISION OF MINES AND GEOLOGY SAN FRANCISCO DISTRICT …gmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_0… · 25.08.1977 · "Geologic and Soil Investigation, Planned

STATE OF CALIFORNIA-THE RESOURCES AGENCY EDMUND G. BROWN JR., Governor

DEPARTMENT OF CONSERVATION

DIVISION OF MINES AND GEOLOGY SAN FRANCISCO DISTRICT OFFICE FERRY BUILDING SAN FRANCISCO, CA 9.tlll

(Phone 415-557-0633)

March 6, 1978

Mr. Gary Bonfiglio Planning Department City of Concord 1950 Parkside Drive Concord, California 94519

Dear Mr. Bonfiglio:

We are placing on open file the following reports, reviewed and approved by the City of Concord in compliance with the Alquist-Priolo Special Studies Zones Act:

Soil and geologic investigation, proposed apartment building, Concord, CA; by Harding-Lawson Associates; February 21, 1978.

//' Geologic and soil investigation, planned warehouse and showroom building, Concord Park and Shop Center, Concord, CA; by HardingLawson Associates; August 25, 1977; with supplement of February 8, 1978.

EWH/mkr

cc: A-P file (2) V W. Darwin Myers

Sincerely yours,

EARL W. HART dffice of the State Geologist CEG 935

Plaonir.ig Department County Administration Building, North Wing P.O. Box 951 Martinez, California 94553

Anlhony A. Oehaesus Director ol Planning

Phone: 372-2024

February 27, 1978

David Golick Planning Department City of Concord 1950 Parkside Drive Concord, CA 94519

Dear Dave:

Contra Costa County

J

Planning Commission Members

Willian1 L. Milano Pittsburg - Chairman

Donald E, Anderson Moraga - Vice Chairman Albert R. Compaglia Martinez Carolyn 0. Phillips Rodeo Jack Stoddard Richmond William V, Walton Pleasant Hill Andrew H. Young Alamo

I have completed my review of the geologic report submitted by the applicant for the proposed Levitz Furniture Building at the rear of the Park and Shop Center, near the intersection of Market and Sutter Streets. The proposed building site is partially within the Special Study Zone delineated by the State Geologist.

The geologic report was prepared by Harding-Lawson Associates and titled "Geologic and Soil Investigation, Planned Warehouse and Showroom Building, Concord Park and Shop Center, Concord, California" (report dated August 25, 1977 with supplement dated February 8, 1978). The field investigation was conducted under the direct field supervision of a registered geologist and the resulting report generally adheres to the guidelines for reports issued by the California Division of Mines and Geology (CDMG Note 49). The primary conc·lusion of the report is that the proposed building site is free of evidence of active faulting.

Findings

1. In my opinion the geologic report and supplement satisfy the requirements of the Alquist-Priolo·Aet:··

2. Trench "A" is located in the area identified as the proposed building site (see Plate 1 in the report of February 8th). On page 10 of the report of August 25th, Harding-La1~son Associates makes specific recommendations for any footings that are located on or immediately adj.acent to the back filled exploratory trench.

•

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David Golick -2- February 2 7, 1978

3. The Seismic Hazards Study of the Concord Redevelopment Area (Earth Sciences Associates, December, 1977) suggests that the building site is approximately 1 ,000 feet southwest of the main trace of the Concord Fault, and approximately 500 feet southwest of the westernmost aerial photo l ineation.

If you have any questions on the geologic report or on my letter-review, please call me (372-2024). I will submitt a copy of the geologic report and this letter-review to Mr. Earl W. Hart of the California Division of Mines and Geology.

WDM:mb

cc: Roger Sharpe Cecil ~food Parker Management Earl W. Hart

Sincerely yours,

Anthony A. Dehaesus Director of Planning

"'-!~(}A,\>.""" \T' W. Darwin Myers RG 3164, EG 946

I I I I I I I I I I I

HARDING - LAWSON ASSOl:IAT~ >

i\•/ 1 '-"' I 1 ' I /).'~ ··7 ' ." 11 . ,., '8

GEOLOGIC A.'ID SOIL INVESTIG,\TIO~l

PLAN:JED WAREHOUSE AND SHOWROOM BUIL:HNG CONCORD PARK AND SHOP CENTER

CONCORD, CALIFORNIA

HLA Job No. 4032,008.03

A Re?ort Prepared For

Parker Management Corpora~ion 1717 North California Boulevard Walnut Creek, California 94596

by

~<!.-~ Frank C. Kresse,

Engineering Geologist - 406

Cecil B. Wood, Civil Engineer - 18671

Harding-Lawson Associates 2430 Stanwell Drive, Suite 160

Concord, California 94520 415/687-9660

August 25, 1977

1 I

INTRODUCTION

I This report presents the results of our soil and geologic

I investigation for a planned warehouse and showroom, Park and s~op

Center in Concord, California. The site is a nearly level paved

I parking lot located along Market Street about 1/3 mile north of

I Willow Pass Road. The east corner of the building area is within

a California Special Studies Zone established by the Alquist-

1 Priolo Geologic Hazards Zone Act of 1972. Our investigation was

performed for Parker Management Corporation between July 18 and

I August 25, 1977. A progress report was submitted on August 16,

I 1977.

The planned building will be a 40- to 45-foot-high, one-story

I concrete and steel structure with a concrete slab-on-grade floor.

Most of the 100,000-square-foot building will be a warehouse, but

I a showroom and o=f ices will be included. The walls will be tilt-up

I concrete and will be supported on columns or strip footings. If

columns are used to support the bearing walls, the loads, as

I supplied by the Structural Engineer, Mr. Paul Juilly of L. F.

I I I I I I

Robinson and Associates, will be as follows:

Column Location

Interior

Exterior and centerline of building

Column Spacing

Center-toCenter

28 to 29 feet

15 feet

Column Load

Dead

16 kips

72 and 65 kips, alternating

1

Dead Plus Live

26 kips

79 and 65 kips, alternating

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HARDING - LAWSON ASSOCIATES

The scope of our work consisted of review of published geo-

cechnical data, int~rpretation of vertical aerial photographs

v ic·v-.'...:.::d. stcreoscor;·i.c~lly, trenching to detect surf ace faulting

and test borings to evaluate subsurface conditions. As listed

in our proposal dated June 18, 1977, the object of our investiga-

tion was to provide you with

1. A description of the site and regional geology

2. Our conclusions regarding the location of the surface traces of active faults within and near the site

3. A qualitative assessment of the general earthquake risk including the probable magnitude, intensity and recurrence interval of future earthquakes

4. Our evaluation of the risk from other possible geologic hazards including ground failure from strong earthquake shaking

5. Recommendations to reduce risk of potential geologic hazards

6. Conclusions and recommendations regarding site preparation, including subgrade treatment for slab-on-grade and paved areas

7. Evaluation of the expansion potential of existing soils

8. Recommendations for foundation types, including depths and allowable soil bearing pressures

9. Estimates of settlement

our geologic study was performed in accordance with the guide-

lines for evaluating the hazard for surface fault rupture established

by the California Division of Mines and Geology. A list of geo-

technical references reviewed along with aerial photographs viewed

is presented at the end of this report.

2

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HAROiNG-LA',\'$0~ ASSOC·A;:_s

FI~L9 EXPLORATION k~D h~BOPATORY TESTI~S

Plate 1 shows the site location and site plan with the loc~

tions of our subsurface field work. A test trench was excav3ted

by backhoe near the east corner of the planned building normal

to the strike of known faulting in the Concord area. The trench

was situated to explore that portion of the new building site that

lies within the State Special Studies Zone. The excavation was

mapped in detail by our geologist. The trench extended a dista~ce

of 160 feet south of the northeast property line and about 10 feet

deep. A test pit was excavated to a depth of 10 feet near the

south corner of the planned building to extend subsurface data

mapped in the trench. The test trench profile and test pit log

are presented on Plates 2 and 3.

We explored the subsurface conditions in other portions of

the building area by drilling six test borings to depths of 15 to

40 feet using flight and hollow auger equipment. Our engineer

logged the borings and obtained undisturbed samples of the soils

encountered for visual examination and laboratory testing. The

boring logs are presented on Plates 4 through 7. The soils are

classified in accordance with the Unified Soil Classification

System described on Plate 8.

Selected samples were tested in our laboratory to deter::iine

moisture content, dry density, shear strength, Atterberg Limits

and consolidation. Test results are presented on the boring logs

in the manner described in the Key to Test Data, Plate 8. Consolid3-

tion test results are presented on Plate 9.

3

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l

J

HA~DING-LAWSON ASSOCIATt_S

s ITE co:~DIT I01'S

Surface Conditions

The site is a lighted and paved 4-acre portion of a parkin7

area for an existing shopping center. Elevations range from 30

to 32 feet (Mean Sea Level Datum) with surface drainage to the

southwest corner.

Subsurface Conditions

Geology

The Regional Geology Map presented on Plate 10 shows the majcr

geologic formations and faults that occur in the San Francisco Bay

Region. Regional geologic structure strikes roughly northwest and

formations vary in age from Jurassic to Quaternary. The site

location, circled on the map, is underlain by Late Tertiary

Quaternary alluvial sediments. The alluvium has been deposited

in the Concord lowlands over Tertiary sedimentary rocks. The depth

of alluvium over bedrock is variable in the Concord area. Bed

rock was not penetrated in our borings which were drilled to a

maximum depth of 40 feet.

Soils

Most of the site has a sandy clay fill up to two feet thick

overlying the natural soils. The fill seems well compacted and

with a low potential for expansion. Below the fill, a highly

expansive and firm residual black clay was encountered to depths

of six or seven feet. Expansive soils tend to shrink and swell with

4

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HAR::JING-LAWSON ASSOCIATE_S

cha~ges i~ moisture co~tent, and can cause heaving and cracking of

sh2llow fou:1~atio11s, slabs-on-grade and pavements.

Below the u~~er natural clay soil, unconsolidated alluviu:n

was encountered consisting of firm clay and silt, and dense sand

and gravel. The soils occur as discontinuous layers or lenses as

i. ··: .. · shown on the mapped profile of the test trench, Plate 2.

•• At the time of exploration, the ground-water level in our

I borings was at depths of 12 to 14 feet.

Seismicity and Faulting

I A seismicity map of the San Francisco Bay Region is presented

on Plate 11, which shows the major active faults, instru:nentally

I located epicenters of earthquakes greater than magnitude 4 since

I about 1929, and only the largest known earthquakes before 1929.

The largest historic earthquake associated with the nearby Concord

I fault occurred in October 1955, with a magnitude of 5.4 (Richter

scale). The active Hayward and San Andreas fault zones strike

I northwest, 13 and 32 miles west of the site, respectively. Two

I major earthquakes on the Hayward fault, 1836 and 1868, produced

strong ground shaking and widespread damage in the Bay Region.

I Five smaller shocks since 1868, also on the Hayward fault, have

produced more localized and much less severe damage. A great

I earthquake occurred on the San Andreas fault in 1906. The shock

I had an estimated Richter magnitude of 8.25 and caused severe

ground shaking and damage throughout most of the Bay Region.

I Shaking intensity experienced in the Concord area has been esti-

mated at VII-IX (Modified Mercalli Scale). The 1906 magnitude

I 5

I "

I I

HAROl."IG - LA'h'SON A ss,)CIATf- s

and intensity represe11t the probable future maxi~u~s for the

I development site.

I The map of sJrface faulting, Plate 12, shows the site loca-

tion in relation to known surface faulting in the Concord fault

I zone. California law requires that special studies be perforneJ

for new construction within specified distances of known active

I fault traces. The site lies on the western limit of the Special

I Studies Zone shown on Plates 1 and 12. In addition to sudden

displacements, slow and relatively continuous fault displacements

I without damaging earthquakes, called "tectonic creep" also occurs

along the Concord and other faults in the Bay Region. The closest

I surface evidence of faulting is over 600 feet east of the site.

I DISCUSSION AND CO::lCLUSIONS

I Based on the results of our investigation, we conclude that

the site is satisfactory for the planned development from a geo-

I technical standpoint. Seismic ground shaking is the only

I significant geologic hazard, and the building should be designed

in accordance with current standards for seismically active

I regions. The existing fill and natural soils will support the

planned building on shallow foundations. To minimize possible

I cracking of floor slabs-on-grade, the expansive natural soils

should be covered with at least 12 inches of select fill.* The

I I I I

* Select fill should conform to the following requirements: (1) free of organic matter; (2) 100 percent finer than 6 inches; (3) liquid limit less than 40; and (4) plasticity index less than 15.

6

HARDING - LAWSON ASSOCIATl::>

e:<:isting fill has lo~ expansion potential and can be used ~or

select fill. GenerJlly, the fill is more than one foot thick

I cn2 bJilding area. Settlement under the higher

col:..:.::~~'l. loads (ES and 72 kips) should be no more than one inch

and postconstruction differential settlement should be less than

1/2 inch. Geologic/seismic hazards that we evaluated are discussed

in the following paragraphs.

Ground Shaking

I The site will experience strong shaking during anticipated

future earthquakes originating on either the Concord, Hayward or

I San Andreas faults. Movement on other faults could also produce

earthquake shaking at the site. The intensity of shaking and

I the resulting lateral forces on structures during an earthquake

I will depend on the distance of the site to the earthquake focus,

magnitude of the earthquake, and response of the underlying soils.

I Within the average building lifetime (about 50 years), the

probable future maximum intensity is on the order of VII-IX

I (Modified Mercalli Scale).

I Faulting

Our subsurface investigation found no indications that would

I suggest active faulting within the site. Furthermore, our

I aerial photo analysis and surface reconnaissance revealed no sur-

face indications that fault traces projected along strike would

I pass through the site.

I 7

I

I I

HARDING- LAWSON ASSOC IA iES

While there is always some possibility for future faultinc:

I in any seismically active region, historical occurrences of sur-

I I I I I I

face faulting have generally closely followed the trace of rncst

recently active faults. Therefore, future surface faulting is f~r

more likely to occur on known active traces of the Concord fault

away from the site.

Liquefaction and Densif ication

Loose, uniformly-grained sandy soils can experience a loss

of strength resulting in a reorientation of grains and settlement

as a result of strong ground shaking. All of the discontinuous

and heterogeneous alluvium penetrated in our borings possesses

high strengths as indicated by the standard penetration count

I shown on the boring logs. Therefore, the sandy soils are unlikcl~·

to densify or liquefy.

I Flooding and Landsliding

I The elevation of the site and its distance from the San

Francisco Bay preclude the risk of flooding from earthquake-induced

I waves such as tsunamis or seiches. There are no nearby large

I bodies of water (reservoirs or tanks} that could flood the site

if they were damaged by an earthquake. We understand that exist-

I ing flood control facilities are designed to prevent areal flood-

ing from exceptional storms estimated to occur once in one hundred

I years.

I There is no risk of landsliding because the soils are firm

and the site and surrounding area are nearly level.

I 8

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HARDING- LA'NSON ASSOCIATES

RECO:·L'·\ENDAT IONS

Site Pre?aratia~ ~~l Grading

The existing asphaltic concrete should be removed or

pulverized in the areas to be graded. Pulverized asphalt and

aggregate base then should be stripped and stockpiled for use as

select fill. Expansive natural soils, if exposed in the building

area, should be excavated as required to provide for at least 12

inches of select fill beneath the slab. The 4 inches of gravel

for a moisture break should not be used as part of the select fill

blanket. The building area then should be proofrolled with heavy

construction equipment. Soft or pumping soils should be excavated

to expose firm soil. The upper six inches of exposed soil then

should be scarified to a depth of at least six inches, moisture

conditioned to slightly above optimum moisture content, and com-

pacted to at least 90 percent relative compaction.*

On-site or imported select fill material should be placed

in lifts eight inches or less in loose thickness, moisture condi-

tioned, and compacted to at least 90 percent relative compaction.

Foundation Support

Foundation support can be obtained with shallow spread foot-

ings bottomed in the firm natural soils or in properly compacted

fill. The trench (shown on Plate 1) for the geologic investigation

* Relative compaction refers to the in-place dry density of soil expressed as a percentage of the maximum dry density of the same material, as determined by the ASTM Dl557-70(C) laboratory test procedure.

9

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I I I I I I I I I I I I I I I I I I

.cl['

HARDING- LAWSON ASSOC!A. ~ES

was backfilled under our engineering inspection. Field density

tests indicate that the backfill was compacted to at least·90

percent relative compaction. However, if footings are placed o~,

the trench excavation, we should inspect the excavations to veri"y

that firm soils are present below the footings. Foundations can

be designed to impose dead load bearing pressures of 2000 pounds

per square foot (psf) and 3000 psf for total design loads, incl~:in~

seismic forces. All footings should be bottomed at least 18 inch~3

below lowest adjacent final grade. Spread and column footings

should be at least 12 and 18 inches wide, respectively.

For resistance to lateral loads, use a passive pressure of

1500 psf against the face of footings. If the area around the

footing is unpaved, the upper 12 inches of soil should be neglected

for computing passive pressure. A friction factor of 0.3 can be

used on the bottom of the footing to develop additional lateral

restraint.

Slab-on-Grade Floors

The soils beneath the floor slab should be kept moist until

concrete is placed. Floor slabs should be underlain by at least

12 inches of select fill. In addition, slabs should be underlain

by at least four inches of clean, free-draining gravel or crushed

rock to provide a capillary moisture break. Moisture vapor will

condense on the underside of the slab and, where migration of

moisture through the slab would be detrimental, a vapor barrier

should be provided.

10

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HARDING- LAWSON Assoc:;, -

P3ve~e~t Thick~~3ses

Iri a"Jto:·1c!J.:.1~ parking areas, we recomme:--~d tha.t flexible ~3.\tE:-

mc~t scc~ic~ c~~sist of two inches of asphaltic concrete placcl

over six i~ches of Class 2 aggregate base. In driveway areas a~j

other areas subject to occasional truck traffic, the thickness o~

the aggregate base should be increased to nine inches.

Prior to pavement construction, underground utilities should

be installed and properly backfilled.

Pavement subgrade should be scarified to a defth of at least

six inches, moisture conditioned, and compacted to at least 95

percent relative compaction to provide a dense, nonyielding sur-

face. Aggregate base material then should be placed and compacted

to at least 95 percent relative compaction. The subgrade soils

and base should be kept moist until the asphaltic concrete is

placed.

Construction Inspection

We recommend that the site preparation and grading, and

excavating for foundations be performed under our engineering

inspection so the soil conditions encountered in the field can

be correlated with the results of our investigation. We shou:'..d

check the quality and compaction of fill material as it is placed.

11

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Plate 1

PLite 2

Plate 3

Plates 4 through 7

Plate 8

Plate 9

Plate 10

Place 11

Plate 12

HAA81NG- LA't.iSO"l ASSOCIATES

PLATES

Site Plan

Test Trench Pro:'ile

Log of Test Pit 1

Logs of Borings 1 through 6

Soil Classification Chart and Key to Test Data

Consolidation Test Report

Regional Geologic Map

Regional Seismicity Map

Map of Surface Faulting

12

--- -------- -----

' Scale: 1"=100'

//

/

Existing Parking

West Lim:t o' Specie:

Studies Zone -

~-r--Existing Buildings

/

/

/

/

/

Reference: Boundary and Topography Survey, by Riffe, Peters and Jones, Civil Engineers, doted 7124177

/

/

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--:-est '3or·cg

• I '4 ~ ~ ~--- : est Trench

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Existing Pork: n g


@ ConBulting Engineers and Geologist•

Job No

\

n 0 0

0

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CO~CORD

LOCATION MAP Not to Sca:e

SITE PLAN

Worenouse and Snowroom Par~ and Shop Center

Conrord, Cat1forr.•'J

PL ATE

1

OVERSIZED -·_. -. -DOCUMENT HAS

BEEN PULLED AND SCANNED WITH THE MAP

FILE. -·--

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~ ~

SheGr Strength (lb;_ .. cq ';\ "' u 2...- ~ -:::-

"' ~

~ c 2:--~ 2! ~ -:E 0 c >- c CL

~ 0 a " " u a 0 :---,-,---r---

, I 0

'

5

10

15

HARDING- LAWSON ASSOCIATES

Consulting Engincc~·s and Geologists

I Job No _4032 ,_D~~._cJ~ _ . __ Appr . --~~Date lf22f!?_ 15

"' CL E 0

V>

LOG OF T~ST PIT

Equipmen t __ Bo_c_k_h_o_e _________ _

Elevation _ __,3'-'l_,,_,_1_* ___ Dote 7/19/77

2'' ASPHALT CONCRETE PAVE1\\U"T l

• , ~GRAY-BROV/N SANDY GF<A'/cL iCP' 1\ de,1se, moist . _t

\ \_YELLCW-BROWN CLAYEY SAND (SC)

--,'\\ den.se, wet, fine- to medium- _J

1 gra1 ned _J

\

LGREEN-GRAY SANDY CLAY (CL) "-medium stiff, wet, (1" thick)

'L BLACK SANDY CLAY (CH) stiff, wet, with roots, discontinuous sli ckensi des and occasion al rounded gravel (gradotional contact at base)

MOTTLED GRAY & BROWN SAND': CLAY (CL) - stiff, wet, with caliche in upper foot (alluvium)

(no free water encountered)

*Mean Sea Leve I Datum as

shown on Topography Survey Plan by Riffe, Peters and Janes, dated 7 /24/77

LOG OF TEST PIT 1

Warehouse and Showroom Park and Shop Center

PLATE

3

, ____ _ -c

I Shear Strength (ib; sq 't'; ., 5 c ~ "' ("") Q 0 Q VI

a o o o o oc

~

u ~-=-

~

_c.- ~

-= Q_ >--Ca_E o~c3a

Equipment 6" Flight Auger

Elevation 30.7 Dote 7/22177 I ~r--~-~-.-~--,.,.,,---~-0,.--~-f?l-.-~--,o ~ 3 O-r--,,,,,,,,,..---~----:2~.~.~A~S7PH~A.,...,..LT=-::C~O~N:-:-::C~R~E~TE-,-~~~-~.,.,..t

-'

I I I I I

25.2 95

23.7 100 5

15.6 11410

I I '----~-'-~~--'-~~'--~-'-~---'

I I I I I I I I I

uu 86)

*Atte berg Limits Liqu d Limil = 67 Plost c Limi = 22 Pl est city Index = ' 5

28.7 94

20.9 108


@ Consult!·ng Engineers and Geologists

I Jot No 4~32,_~08. 03 , r, ~ 8/1/77 Aopr · , . Date

'6

4" AGGREGATE BASE ~ MOTTLED GRAY SANDY SILT (ML)

stiff, moist BLACK SANDY CLAY (CH)

stiff, moist

BROWN SANDY CLAY (CL) stiff, moist with grovel layers

water level 7 /22/77

LOG OF BORING 2 Equipment 6" Flight Auger

Elevation 30.5 Dote 7/22/77

2" ASPHALT CONCRETE ....J

4" AGGREGATE BASE BROWN SANDY CLAY (CL)


stiff, moist

BROWN SANDY CLAY (CL) stiff / moist

MOTTLED BROWN-GRAY CLAYEY GRAVEL (GC) - dense, wet

MOTTLED BROWN SANDY CLAY (CL) stiff, saturated

(boring backfilled before water level stabilized)

LOG OF BORINGS 1&2


PLATE

4

·:·· > -'I

' -I I I I I

Shear Strength (lbs/sq ft)

0 0 0 N

0 0

"' 0 0 0

0 0 ;.fj

~

u

..8- --=-2' .:::::.. Q)

-:f Cl->.,CCL E ..... Q) Q) 0

0 0 0 V>

LOG OF BORING 3

Equipment 6" Flight Auger

Elevation 30.7 Date 7/22/77 ~---

' ' o~~~~~~~~~~~~~~~i

2" ASPHALT CONCRETE _L

I I j

I I

UU Sc 0 x x

25.4 97

5 20.4 105

10

15

28.6 0

95

31.8 81

5

7. 1 120

15


@ Consulting Engineers and Geologists

4032, 008. 0_3 ~ __ Appr _'} ~_Date _ 8/1 /77

17

4" AGGREGATE BASE _,' BROWN SANDY CLAY (CL) ~1


stiff, moist

BROWN SANDY CLAY (CL) stiff, mai st

{baring backfilled before water level stabilized)

LOG OF BORING 4

Equipment~~6-"~F~li~g~h~t~A~u~g~e~r~~~~~~-Elevotian 30.6 Date 7/22/77

2" ASPHALT CONCRETE 4" AGGREGATE BASE BROWN SANDY SILT (ML)

stiff, wet BLACK SANDY CLAY (CH)

stiff, moist

_J _J '

u:: I

BROWN SILTY SANDY GRAVEL (GM) dense, moist

(boring bock fi 11 ed be fore water level stabilized)

LOG OF BORINGS 3&4


PLATE

5

I I I I I I I I I I I

Shear Strength {lbs/sq ft)

r--1

I Cons lidati n test

~

~ ~

~ u g__ 0. ~

~ -"' - ~

~ c: c-~

.2 "' ..r; ~ - ~ a. ·- c: >.. c: ~ (l ~ "' "' 00 0

26. 1 97

27.6 95 25.2 97 5

9.6 10

26.0 105 15

20

27 .1 94

25

30

35

"' 0. E c .,..

LOG OF BORING ::i

Equipment 6" Flight fa.uger

Elevation 30. l Dote 7/22/77

2" ASPHALT CONCRETE 4" AGGREGATE BASE BLACK SANDY CLAY (CH)

stiff / moist

BROWN CLAYEY SANDY GRAVEL {GC) - medium dense, moist

BROWN SANDY CLAY (CL) stiff, saturated

increase in sand content

I i.-=;;;;;;;;;;;!;;;;;;;;;:!;:;;::;;;;:!;;:;;;;;;;;;!;;;;;;;;;;;;;:,__~~-!40~~.:....~~~~~~~~---.~~~ I HARDING - LAWSON ASSOCIATES

@ Cons1ilting Engincrrs a;id Geologists

A ppr ' ! ~Date 8/1/77 .

. '"'·

LOG OF BORING 5


PLATE

6

I LOG OF BORING 6

I Shear Strength :;\b;/cq ft)

Equipment 8" Holh·c; Auger

Elevation 31.0 Date 8/1 /77

I I

o~~--~~~~~~~~~~~~--~~~~

2" ASPHALT CONCRETE ~


5

JO

15

20

25

30

35

40

I HARDING - LAWSON ASSOCIATES

I , :·': 4032,008.03 · ~_..,Date 8/24/77

·9

4" AGGREGATE BASE ~ BROV1N SANDY SILT (ML)

stiff, wet BLACK SANDY CLAY (CH)

stiff, mai st

BROWN CLAYEY SANDY GRAVEL (GC) - medium dense, moist

water level 8/2/77

BROWN SILTY CLAY (CL) medium stiff, saturated

increase in sand content

MOTTLED RED-BROWN SANDY CLAY (CL) - medium stiff, saturated

MOTTLED BROWN CLAYEY SAND (SC) - medium dense, saturated

LOG OF BORING 6


PLATE

7

-

MAJOR DIVlSIONS I TYP1CAL NAMES I

I

I GW • '! . f 1 N!ll Ol:.Of:O G•>VhS. G«~V!L - iA"'O M1)(!"\...Sli

! CUA ..... Gll>.Vt:lS -· w1l'M .rnL! Ot .... (J) - ' G~AVEl..S I NO llNU , I ; •Q()I~ v Got.:..ot::i G•,.;f.S, G~.avfl. SANO ...J > jGP

o°' • -· ..... IXT'JllB

(J)~ ~ n.AN 'l'IAL'

! GM ;; SILTY OlA;HS, '00tLY GiADfO GlAVt:l • S.A"'O -cc....iH l"tACTlOr-1 I

z 15 ·..AllGU 1'1-IAN

I Gi.AVfLS Wln4 1 j S1~ T 1t1U:X'!"...an

o< "'O ' SIN! Sl2! 0\1!11: 11' 'JNfS r QC ~ CL.A...YY Gt.-.·1hS, 'OOIL'>' GlAOlfO OlAVIL - SANO. l&J ~

z3 ' I ,.,. "...-A CLo\'1' .... !X'!"JlfS

-;;: ~ T P"' • • a: ~ I$'# i • • j Wfl~ GIADtC iA"105, G ..... VfLlY SANOS Ill < Cl.I.AN SANOS

l&J ~ W:™ LITTU OI ~ ....

SANOS NO FINU '" .. (J) z •• i e • 1 'OOILV ~AOfO SA"°'OS, GlJi.Vl..L'I' SANOS

a: i ... MOii! rHAN ..... l, .,1•;J• Slll"Y S.ANOS c- COAISI 'UCTION 'SM "OQl, l' GlADfO SANO • SILT s; IS SMALLl!lll niAN SANOS Wlft-1

1•._1• MIXTVlfS

NO. 4 SllVI SIZI OVEt !1' FINU ·~ SC v~ C.AYfY SANOS, 'OOl:LY c;a..:.oto SAND- ClA'T'

;.,~,. MlllrutfS

0) ~ I, 1N0t:;...,N1c ~:~'1 ~"'o vov "'"'f iANDS 1ocir

ML I i 'LOIJ SIL f'Y OI' Ci..AYrY ~IN! SANDS Ct ...J ~ ; CUt'l't~ SIL rs #IT~ SllGl"T ':.>5TlCJT"I':

-~ SILTS ANO CLAYS ~ INQl:G .. ~IC (;,,.\Y'S '.)J -°""' ~o W"OlUM '\.A.5nc1rY o. Cl ') G•A..-fLLY (LAY1, 5AN0Y (i..AYS, SllrY (CAYS, ' (J) z

o! LIQUID LIMllT Lf:SS l"'.4.N $0 LfAN C..AYl

OL ::1 '' I I 11 OIGANIC CL.An ANO OIGANIC SILTY C:.>Y! Of l&J = I I l :.0\111' 'LASTICITY z~ -1 I

~~ : MH I iNOfG .. NI( SILn, Ml0.CIOV5 QI OLATOM.lt.CIOUS ; J1Nf SANDY Oil Sllr'Y SOtLS, HAStTC SILTS

~ SILTS ANO CLAY9 ~ INOIGANtC CLAY1 ~ ~G~ "LAlitTClTV, l&J 5 CH

UQUIO LIMIT G.l(AT!I fl1AN $0 '/ JAT CLAY1 :!: l

~ .... ; OH 0-GANIC CLA.,... C>' Mf:OIUM TO HIGH "1..AST!OTY, 'l,,1 OtGANIC SILn

~·

·1

I I

HIGHLY OiltGANIC SOI L9 •• s "UT AMO 0Tl1U '"'IGHLY OIGANIC SOILS

!,!NIFIED SOIL CLASSIFICATION ~Y~TEM I I

~Ma.&; ~SliNATI~

•·u .. 111 ......... s •• ,.1. 181 1.,lk •• c1. 11 1t1c••l•" s .... 1. I STRENGTH TESTS

kQVVVSi YAN( SHfAI TfST UNCONflNfO COM,tfSSION rt ST

' •"•Ill L • L••••••••r I

1000 (lot O) r ~ OtlfCT 5,_.fAI TfST 1000 (30 01 tg x g ,. TIJAXIAL COM,lfSSION TfST

t co· c ..... 1111•••• • o...... 1 LI uu . Unc•n1ollll•••ll • u .. dr•IR•ll

Cu • Co•.,olill•••ll • u .. 11,.1 ... 11

Moh•••• '•"'•"' oltor 1.,. ( .. ) CO• c.,,,.1111•••11 • Orol,.•11 Suon N••••I •• 5"••• ,1 .... c,,fJ

l/2 o •• , •••• s ..... f•·') ,.,.1,,..,,. c ..... ,,, •"•• r.,, "'' c ... 11 .. 1 .. , 5,, ... - 0'

3 r,,q

!S t;;Y TO TEST DATA

I I I

HARDING· LAWSON ASSOCIATES SOIL CLASSIFICATION CHART PLATE @ Cons1dting E.."'11gint·crs and Gf'o[ogists AND

8 KEY TO TEST DATA

Job No._ ~ J32, O_()B. 03 _ "':- 8/1/77 Warehouse & Show rm Park & Shop Cntr A ppr Da.!e

I I

""41~75 ,.

I I I I I I ~

Cl

I §;

I I

01 02 030405

PRESSURE I psfx !000!

I 2 3

I : i

!'-.'.._. !

·~ "-. ! I ~

I I i : i !

! ' i I

I i i '

I i I I

4 5 10 20

\Ii ! I ' I !

I ~' i i ' ' I ! I \i I ' i I I\ ' ' '

I :-... r--. n !

' I h--..

: i !\ I

IT ,' ! I I I "N.._ ' \ I I ! ! ' ' ' N:i

30 40 50

I ' I

I+ t t r -

!

' I

' . '

'

i I

i I I !

I I

I ' I I

>---+-+-<-+-+--+--+-·~--...-~r-+-t-+-+-t--+-t-+-+-+--+--+--+-t-+-+-~-+-+-+-+--+--+-+-+-+--+--+-+--+-f-i

+++~ i

i l : 0.1 0.2 0.3 0.4 0.5 2 3 4 5 10 20 30 40 50

TYPE OF SPECIMEN Undisturbed BEFORE TEST AFTER TEST

DIAMETER (,n I 2.43 I HEIG~-f~(1n) 0.80 MOISTURE CONTENT WO 27 .6 % *f 25.5 %

OVERBU~DEN PRE SS, Do psf VOID RATIO •a 0.786 ., 0.714

I PRECONSOL P~ESS,Pc 4000 psf SATURATION So 96 % Sf 98 %

COMPRESSION INDEX, Cc 0.203 DRY DENSITY ~d 95 ocf 'id 99 pc ~

LL --- PL --- Pl --- Gs 2 .73 •~~~~~~~~~'--~----i CLASS<FICATION Black Sandy Clay (CH) SOURCE Baring 5 at 3.6'

I HARDING - LAWSON ASSOCIATES

I . oh .,., 4032, 008. 03 'J- Dcire 8/24;77

CONSOLIDATION TEST REPORT Warehouse and Showroom

Pork and Shop Center Concord, California

PLATE

9

'I

I I I I I I I I I I

''""''""" o,,.~,oi;• .,, .,,..,.,,,,. '" ..... '"'''· ""''"""''""'' '"''" '"'""on•.'"'"'°'"'"' ...... ~·~··

•-••·•01Conoc occH

0

L Mod"'~"I• <OMOlodol•d to

... h "'""""'""'"" "d"'""'"'' •CC" -Sood"°"'• '"""· """ cooqlo.,o•o". 1ornll) "0-005' oo" bosol• c

~"""'"" ond ""d""''

Site Loc"t ion

[_~J


Consulting Engincrrs and r;eologists

Job No . 403_2,008.03 Appr , Ii , Date 8/1 7 ;77

22

g, •' _,_ \.( I

·;•

I

/·

REGIONAL Gf.OLOGIC Mf.f-

Warehouse and Showroom Purl.. ar;J Shop Center Concord, (_Glifornio

,, '

10

•~r-----------~


APRIL

0

• Santo Roso \

\\ \ ~ · ..

0

JUNE, 1838, 7. 0 __ .--21,1868, 7.0

0

\ \ 0

1, ., I, 1911, 6.6

'• ,,

0 0 0

0 25 miles

EARTHQUAKE EPICENTER MAGNITUDE LOCATION

4.0 - 4.9 0

5.0 - 5.9 c,

6.0 -6.9 • Dote

7.0-7.9 • Dote

8.0 - {I Dote

REFERENCES

OCT. 22 ,1926, 6.1 ~

and Moonitude shown

and Moonitude shown

and Moonitude shown

0 •

0

Carmel

• •

0 0

0 0

0 Site Location

•

I. California Division of Mines and ~~olooy, 1972, "Preliminary Earthquake Epicenter Mop of California, 1934-1971 (June 30), Seismic Safety Information - 72-3.

2. California Deportment of Water Resources, January 1964, "Crust a I SI rain and Foul 1 Mavemenl I nves tiootion," Su I let in No. 116 - 2.

HARDI NO· LAWSON ASSOCIATKS

@ Co,..ulting Engineers and Geologist1

Job No. 4032 I 008 o 03 Appr: r H Date 8/1 7 /77

23

REGIONAL SEISMICITY MAP

Warehouse and Showroo1" Park and Shop Center Concord, California

PLATE

11


_/CC"·;CQRD I

i I '

Turning point / for zone limits

i:',4!JL T, -N1tn notations 1nd1cat:ng e•:dence of

faulting, snor 1 dasr.erj ~nere 1nferre·.::!

queried wne.~e ~nt.erto;n

?::-~o;,,.:_e ~~ ,::~e: rJ !>..~!'.:..-.

SPECIAL STUDIES ZONE

0 1000 2000 4000 6CCO 'eer ~~~~---~~~

0 SITE LOCATION

Source' References 5 and 14.

HAi.DINO •LAWSON ASSOCIAT•S

~ Couulti"ll Engin .. r1 and G•ologi1t1

..tlJ No. 4032 I 008 • 03 Appr ' .; ,_Date 8/1 7, 77

SCALE

MAP OF SUEFACE FAULTIN·:i

Vv a rehouse cnJ Showroom Park .m~ Shop •::enter

Concord, Cali 'orni~"J

PLATE

12

I I I I I I I I I I I I I I I I I I I


LIST OF REFERENCES

1. Borcherdt, R. D., 1975, Studies for the Seismic Zonation of the San Francisco Bay Region, U.S. Geological Survey, Professional Paper 941-A.

2. Brown, R. D., Jr., 1970, Faults That Are Historically Active Or That Show Evidence of Geologically Young Surface Displacement, San Francisco Bay Region, USGS and HUD.

3. California Division of Mines and Geology, 1972, Earthquake Intensities, 1819-1969, Seismic Safety Information 72-4.

4. California Division of Mines and Geology, undated, Geologic Map of Contra Costa County, showing Mines, Quarries and Gas Wells, Journal, Vol. 54, No. 4, Plate 5.

5. California Division of Mines and Geology, July 1, 1974, Walnut Creek Quadrangle, Special Studies Zones.

6. Contra Costa County Planning Department, 1975, Seismic Safety Element, Public Hearing Draft.

7. Greensfelder, R. w., August 1974, Maximum Credible Rock Acceleration from Earthquakes in California, Map Sheet 23, California Division of Mines and Geology.

8. Jennings, Charles W., 1975, Fault Map of California with Location of Volcanoes, Thermal Springs and Thermal Wells, California Division of Mines and Geology, California Data Map Series, Map No. 1.

9. Lawson, Andrew C., 1908, The California Earthquake of April 18, 1906, Report of the State Earthquake Investigation Commission, Carnegie Institution of Washington (1969).

10. Limerinos, J. T., et al, 1973, Flood Prone Areas in the San Francisco Bay Region, California, Interpretive Report 4, USGS and HUD.

11. Nilsen, Tor H., 1973, Preliminary Photointerpretation Map of Landslides and Other Surficial Deposits of the Concord 15-Minute Quadrangle and the Oakland West, Richmond, and Part of the San Quentin 7-1/2-Minute Quadrangle, Contra Costa and Alameda Counties, California, Basic Data Contribution 57, USGS & HUD.

12. Protzman, D. L., 1963, Surface Geology, Contra Costa County, unpublished, Tidewater Oil Company.

25

11 :1 '

I, I I I I I I I I I

HARDING- LAWSON ASSOC IA 7E: 3

13. Seed, H.B., I. M. Idriss, September 1971, Simplified Procedure for Evaluating Liquefaction Potential, Journal of Soil ~echanics and Foundations Division, American Society of Civil Engineers.

14. Sharp, R. v., 1973, Map Showing Recent Tectonic Movement on the Concord fault, Contra Costa and Solano Counties, Cali=ornia, Basic Data Contribution 55, USGS and HUD.

Black and white aerial photographs of Contra Costa County Source: Pacific Aerial Surveys, 5/27/76, Scale: l" = 1000'

Code Roll Flight Line Exposure

AV 251 05 28 - 29

26


3 copies:

2 copies:

1 copy:


DISTRIBUTION

Parker Management Corporation 1717 North California Boulevard Walnut Creek, California 94596

Attention: Mr. King Parker, Jr.

c. M. Peletz Company 1415 Rollins Road Burlingame, California 94010

Attention: Mr. Douglas C. Curtis

L. F. Robinson and Associates 80 Stonestown San Francisco, California 94132

Attention: Mr. Paul Juilly

GVH/GEU/FCK/CBW/jd

27

Documents

DIVISION OF MINES AND GEOLOGY SAN FRANCISCO DISTRICT …gmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_0… · 25.08.1977 · "Geologic and Soil Investigation, Planned