date: april 18, 1994...1993/04/01 · 711 main street, huntington beaeh, ca 92648, (714) 536-1075...

STATE OF CALIFORNIA • THE RESOURCES AGENCY

DEPARTMENT OF CONSERVATION DIVISION OF MINES AND GEOLOGY BAY AREA REGIONAL OFFICE 185 Berry street, s~fte 3600 San Francisco, CA 94107 Phone (415> 904-7707

ATSS 539-7707 Fax (415) 904·7715

Peter Lyons Director of Planning City of Rosemead P.O. Box 399 Rosemead, CA 91770

Dear Mr. Lyons:

PETE WILSON, Governor

March 10, 1994

We are placing on open file the following reports, reviewed and approved by the city of Rosemead in compliance with the AlquistPriolo Earthquake Fault Zoning Act (formerly the Alquist-Priolo Special Studies Zones Act):

Preliminary geotechnical and fault investigation for the proposed Senior Citizen Apartment Building, Rosemead, CA; by Leighton and Assoc.; 4/1/93 1 with response of 2/15/94. (Report is missing Figure 1, Plate l, and Appendices A to E.)

Geologic fault line investigation, proposed commercial development, SW corner of Fern Ave. and San Gabriel Blvd., Rosemead; by Ray A. Eastmen; 11/5/92.

Please note that there are several missing illustrations and appendices to the first report. Most important are the Boring and Trench Location Map (Fig. 1) and Log of Fault Trench T-1 (Plate 1) . It would be appreciated if these materials were provided to complete our file.

EWH:ra cc :AP file (2)/

Sincerely,

;·rl Earl W. Hart, CEG 935 Senior Geologist &

Program Manager

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LEIGHTON AND ASSOCIATES, INC. Geotechnical and Enviranmental Engineering Consultants

To:

Attention:

City of Rosemead Planning Department

April 1, 1993

8838 East Valley Boulevard Rosemead, California 91770

Mr. Peter Lyons

Project No, 2920024-02

Subject: Preliminary Geotechnical and Fault Investigation for the Proposed Senior Citizen Apartment Building, City of Rosemead, California

Introduction

In accordance with your authorization, we have conducted a preliminary geotechnical and fault investigation at the site of the proposed senior citizen apartment building, located at the northwest corner of Angelus Avenue and Klingerman Street, in the City of Rosemead (sec Site Location Map, ). The purpose of this investigation was to evaluate the geotechnical conditions at the site with respect to the proposed development. Additionally, the site is located within a recently delineated Alquist-Priolo Fault Zone. As such, an evaluation of the site with respect to active faulting was also rcquin:d. We have used a Site Plan provided by you to prepare our Boring and Trench Location Map, Figure 1, as the base map for this investigation. 111is report summarizes the results of our investigation and provides our conclusions and recommendations for design and construction.

Accompanying Maps and Appendices

Site Location Map (2000-scale) - Page 2 Figure I - Bming and Trench Location Map Plate 1 - Log of Fault Trench T-1 Appendix A - Geotechnical Boring and Trench Logs Appendix B - Lllboratory Test Data Appendix C · Regional Seismicity Map,

Table of Seismic Parameters, and Seismic References Appendix D - General Earthwork and Grading Specifications Appendix E - References

1470 SOUTH VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765

Rear of Text In Pocket

(714) 860-7772 •(BOO) 777-2286 FAX (714) 860-1089

To:

Attention:

LEIGHTON AND ASSOCIATES, INC. Geotechnical and Environmental Engineering Consultants

T R A N S M I T T A L

State of California Department of Conservation Division of Mines and Geology 185 Berry Street, Suite 3600 San Francisco, California 94107 Mr. Earl W. Hart

Date: April 18, 1994

Project No. 2920024-02

Transmitted: The Following: For:

...!._ Mail/UPS Draft Report Your Use

Courier

Pick Up

Subject:

1 EaFinal Report

Proposal

Extra Report

Other

....!... As Requested

l) Preliminary Geotechnical and Fault Investigation for the

Proposed Senior Citizen Apartment Building, City of Rosemead,

California, dated April 1, 1993

2) Response to Preliminary Review of Geotechnical Report for the

Proposed Senior Citizens Housing Complex, Angelus Avenue,

City of Rosemead, California, dated February 15, 1994

LEIGHTON AND ASSOCIATES, INC.

By: Phil Buchiarelli

1470 SOUTH VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765 1909) 860-7772. [800) 777-2286 FAX [909) 860· l 089

MAYOFI: 1-lJJl::ll:.K I W. 1:-\Hl.lf-SGH

MAYOR PAO YfM: JO[ VA!:>UUI:..::'.

COUNCILMEMBERS: MARr.;ARrT CLl\nK nFNNIS MCDONALD C:i/\RY /\. TAYLOn

8838 E. VALLEY BOULEVARD • P.O. BOX 399 ROSEMEAD, CALIFORNIA 91770 TELEPHONE (818) 288-6671 TELECOPIER 8183079218

March 7 1 1994

Earl w. Hart Senior Geologist & Program Manager Department of Conservation Division of Mines and Geology 185 Berry street, suite 3600 San Francisco, CA 94107

Dear Mr. Hart:

Enclosed you'll find two geologic reports for two separate "projects" required under the State's Alquist-Priolo Special studies Zones Act. Attached to each report are the required third-party review.

To date, there have been no other "projects" as defined in Section 2621.6(a) of the Alquist-Priolo Act submitted within the zone.

In addition, the City of Rosemead is amending our General Plan and Municipal th Alquist-Priolo re-classification.

Si erely,

Planning

PL/jcp \

Attachments

D { 23)

now in the process of Zoning Code to reflect

Paul Davis, Consulting Engineering Geologist

711 Main Street, Huntington Beaeh, CA 92648, (714) 536-1075

February 22, 1994

City of Rosemead 8838 E. Valley Blvd. Rosemead, Ca 91770

Attention: Mr. Peter Lyons

Subject: Results of Independent Review of Geotechnical Reports By Leighton and Associates, Inc. for the Proposed Senior Citizen's Apartment Complex Angeles Avenue, Rosemead, California

Dear Mr. Lyons:

In accordance with your authorization dated January 19, 199~, This letter presents the results of our independent (third party) review of geotechnical reports prepared for the subject site by Leighton and Associates, Inc., dated April 1, 1993 and February 15, 1994 (References 2 and 3). The site is situated within a recently delineated California Alquist-Priolo Special Studies (fault) Zone. The main purpose of this geotechnical review is to evaluate whether the data presented in the Leighton and Associates reports are complete and adequate and in general conformance with State of California guidelines for evaluating the hazard of surface fault rupture (Reference 1).

The personnel at Leighton and Associates cooperated with the review investigator and readily provided the necessary reports and pertinent references.

Our scope of work to perform this independent review consisted of the following tasks.

1. A review of the geotechnical reports, graphics and exploration logs dated April 1, 1993 and February 15, 1994,

2. A site visit, and,

3. A review of the cited references used to prepare the reports.

A preliminary review of the Leighton and Associates report dated April 1, 1993 revealed that several additional items needed to be addressed. The requested items were listed in a letter dated February 1, 1994 (Reference 4), and were subsequently provided in a report dated February 15, 1994 (Reference 3).

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Paul Davis Consulting Englnaering Geologist

The referenced Leighton and Associates reports provide discussions of regional and site geologic and seismic conditions. Their fault investigation included a review of stereoscopic aerial photographs, excavation and logging of a backhoe trench across the site, a discussion of nearby fault s~udies, and a review of recently published literature pertinent to nearby faulting and tectonics. In addition, their report addressed site seismicity and liquefaction potential.

The Leighton and Associates reports concluded that the site is expected to experience high levels of ground shaking within the projected life of the structure, but no active traces of the Whittier Extension fault were observed onsite. Potential damage due to liquefaction is considered in the report to be very low.

Findings and conclusions presented in the Leighton and Associates reports appear to be supported by the data presented, and are in substantial agreement with data presented by other professionals in the area. In summary, as a result of this independent review, the reports by Leighton and Associates are believed to meet the general requirements for preparation of Alquist-Priolo Special Studies Zones reports, consistent with the present state of practice in Engineering Geology.

Sincerely,

/7 7 ';;=::.,· ,.,~ r,·-----0~~ . / Paul Davis, CEG 320

copies: ( 3) addressee

this review project. Please do not further questions on this or any other

(1) Leighton and Assoc., Mr. Eldon Gath

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...

Paul Davis Consulting Engineering Geologist

REFERENCES

1. California Division of Mines and Geology, 1975, Guidelines for Evaluating the Hazard of surface Fault Rupture, CDMG Note Number 49.

2. Leighton and Associates, Inc., 1993, Preliminary Geotechnical and Fault Investigation for the Proposed Senior Citizen Apartment Building, City of Rosemead, California, (Project No. 2920024-02), April 1.

3. -----------------------------, 1994, Response to Preliminary Review of Geotechnical Report for the Proposed senior Citizens Housing Complex, Angelus Avenue, City of Rosemead, California, (P.N.2920024-02), February 15.

4. Paul Davis, Consulting Engineering Geologist, 1994, Third Party Review of Geotechnical Report By Leighton and Associates, Inc., dated April 1, 1993, Proposed Senior Citizen's Apartment Complex, Angeles Avenue, Rosemead, February 1.

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

LEIGHTON AND ASSOCIATES, INC Geotechnlcal and Environmental Engineering Consultants

PRELIMINARY GEOTECHNICAL AND FAULT INVESTIGATION FOR TIIE

PROPOSED SENIOR CITIZEN APARTMENT BUILDING,

CITY OF ROSEMEAD, CALIFORNIA

April 1, 1993


Prepared for:

CITY OF ROSEMEAD Planning Department


1470 SOUTH VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765 (909) 860-7772. [800) 777·2286 FAX [909) 860· l 089


LEIGHTON AND ASSOCIATES, INC. Geotechnical and Environmental Engineering Consultants

To: City of Rosemead Planning Department

April 1, 1993




Subject: Preliminary Geotechnical and Fault Investigation for the Proposed Senior Citizen Apartment Building, City of Rosemead, California

Jntroduction

In accordance with your authorization, we have conducted a preliminary geotechnical and fault investigation at the site of the proposed senior citizen apartment building, located at the northwest corner of Angelus Avenue and Klingerman Street, in the City of Rosemead (sec Site Location Map, Page 2). The purpose of this investigation was to evaluate the gcotcchnical conditions at the site with respect to the proposed development. Additionally, the site is located within a recently delineated Alquist-Priolo Fault Zone. As such, an evaluation of the site with respect to active faulting was also required. We have used a Site Plan provided by you to prepare our Boring and Trench Location Map, Figure 1, as the base map for this investigation. This report summarizes the results of our investigation and provides our conclusions and recommendations for design and construction.

Accompanying Maps and Appendices

Site Location Map (2000-scale) - Page 2 Figure 1 - Boring and Trench Location Map Plate l - Log of Fault Trench T-1 Appendix A - Geotechnical Boring and Trench Logs Appendix B - Laboratory Test Data Appendix C - Regional Seismicity Map,

Table of Seismic Parameters, and Seismic References Appendix D - General Earthwork and Grading Specifications Appendix E - References

1470 SOUTH VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765

Rear of Text In Pocket

1909) 860-7772. [800) 777-2286 FAX [909) 860-1 OB9


!': I ! ~V<'. .· I . '" ' ' ;!:I 1 I

~11\.: " .

0 I scale

2000 4000 I

feat

SITE LOCATION MAP

Base Map: U.S.G.S. El Monte Quadrangle

F

SENIOR CITIZEN APARTMENT BUILDING

CITY OF ROSEMEAD, CALIFORNIA

Project No . ....:2oZ.9.:20~0~2.:4!'--..l;0~2 __ _

Date April 1, 1993

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CTJ[IJ 1040 889


2920024-02

Scope nf Work

The scope of this preliminary geotechnical investigation included the following tasks:

• Review of availahle literature concerning the geotechnical conditions at the site. This included a review of the appropriate fault evaluation report.

• Stereoscopic review of sequential aerial photographs lo observe historic conditions of the site and possible geomorphic expression of faulting.

• Excavation, logging, and sampling of two exploratory horings to a maximum depth of 51 feet to evaluate the subsurface conditions.

• Excavation and logging of a trench across the site to observe conditions nf any faulting.

• Laboratory testing of representative samples obtained from the borings.

• Analysis nf collected field and laboratory data to evaluate the site soil and fault conditions.

• Engineering analyses.

• Preparation of this report presenting our findings, conclusions, and recommendations for site development.

Site Description and Proposed Development

The subject site is an approximately triangular shaped, flat parcel of land currently covered with a moderate growth of vegetation. The site is bounded on the west by the Alhambra Wash, on the east by Angelus Avenue and on the north by existing houses. The proposed development is still being evaluated at this time but is expected to consist of construction of a three-story senior citizen apartment complex. The first floor of the apartment complex may be used for parking, with the upper two floors consisting of living quarters. The foundation loads for the three-story building have not been developed and are not available to us at this time. We understand that the first tloor parking structure will either be constructed at grade or below grade (subterranean) but that a final decision has not been made.

Subsurface Exploration

Two exploratory borings were drilled to a maximum depth of 51 feet below ground surface using an eight-inch diameter, hollow-stem auger, Type CME 55 drill rig. Boring locations were selected to provide data necessary to develop subsurface information with respect to the proposed development as shown on the Boring and Trench Location Map, Figure 1. Soil samples from the borings were

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2920024-02

obtained at selected intervals by Standard Penetration Test (SPn and California Split Barrel samplers. Representative bulk samples were also obtained at selected intervals. All samples were transported to our laboratory for testing. The geotechnical boring logs are presented in Appendix A.

In addition to the two borings, a trench was excavated across the site to explore for possible faulting. The trench was excavated across the northern portion of the site and extended 115 feet from Alhambra Wash to the fence along Angelus Avenue. The trench was excavated to a maximum depth of about 15 feet. The trench log is presented as Plate 1.

Laboratory Testing

Laboratory tests were performed on representative samples to determine:

• Maximum dry density and optimum moisture content;

• In situ moisture content and dry density;

• Grain size distribution;

• Consolidation characteristics;

• Soil strength characteristics:

• Soluble sulfate concentration; and

• pH and resistivity

The results of in situ moisture content and dry density are presented in our geotechnical boring logs in Appendix A. The results of other laboratory tests are presented in Appendix B.

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IEIGllTON AND ASSOCIATfS, INC.


2920024-02

FINDINGS

General Soil Profile and Ground Water Conditions

Based on the interpretation of field and laboratory data, the subsurface soil profile beneath the proposed building consists of loose to medium dense, moist, fine to coarse-grained, dark brown to brown, silty sand to a depth of about four feet. This material was underlain by slightly plastic, fine to medium-grained, reddish brown to brown, moderately firm, sandy clay to a depth of approximately nine feet below ground surface. The sandy clay layer is underlain by brown, medium dense to dense, fine to coarse-grained, silty sand to a maximum depth investigated of 51 feet. The silty sand generally contains a low percentage of gravel, with sizes ranging up to one inch. Occasional thin layers of interbedded sandy silt were encountered within lhe silty sand layer.

Ground water was encountered in both of our borings. Ground water was encountered at 43 feet and 47 feet in Borings B-1 and B-2, respectively.

The upper five feet of soil is generally loose to medium dense. As exposed in our fault trench, this material consists of uncontrolled artificial fill, historic Ouvial deposits and topsoil. The dry density of the soil between five feet and 30 feet ranges from 112 pcf to 123 pcf. The moisture content of these soils ranges from 2.4 percent to 16.3 percent.

Uncontrolled artificial fill, consisting of loose, sandy silt and sandy clay, was exposed in our fault trench adjacent lo Alhambra Wash. This is probably backfill behind the concrete channel wall (see Plate 1). This material is unsuitable for the support of structures.

Faulting and Seismicitv

The proposed site of the senior citizen's apartment complex lies within a recently delineated AlquistPriolo Special Studies Zone. These regulatory zones, established hy the state geologist encompass the surface trace of faults that the state geologist has evaluated as sufficiently active and well-defined according to the Alquist-Priolo Special Studies Zones Act. An active fault is one which has exhibited earthquake activity in Holocene times (the last 10,000 to 11,000 years). A fault which has moved <luring the last two million years (Pleistocene time), but not proven by direct evidence to have moved, or not moved, within Holocene time is considered to be potentially active. Any fault proven by direct evidence to be older than Holocene (one which docs not displace rocks 10,000 to 11,000 years old) is considered inactive. In general, the position of the special study zone boundary is established about 500 feet away on both sides of major faults.

In 1991, a possible extension of the Whittier fault was zoned in the Rosemead area by the state geologist (Reference 2). The Whittier fault which is an extension of the Elsinore fault is exposed along the southern margin of the Puente Hills from Corona to Whittier. Until recently, the surface expression of the fault had not been recognized in the Whinier Narrows area. The Rio Hondo and

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~ 11.i11 11111

II 11111 I I I

' LEIGllTO/fl All/J ASSOCIATES, lllC.


2920024-02

San Gabriel Rivers drain through the pass between the Puente Hills and the Montebello Hills and would rapidly destroy any surficial evidence of past movement. Immediately northwest of the narrows area, however, a prominent scarp and other possibly fault related features such as linear ridges, swales, and vegetation differences were observed in aerial photos taken of the area in 1927. These photos were reviewed for the Fault Evaluation Report (Reference 6). Although development has disturbed the landscape considerably, the scarp is still noticeable today. In the immediate vicinity of the site, the scarp is present near the intersection of Klingerman Street and Angelus Avenue southwest of Alhambra Wash.

As part of an investigation for the Southern California Earthquake Center and for Southern California Edison, Leighton and Ao;sociates has excavated several trenches across the probable trace of the fault southeast of the Angelus Avenue site near Delta and Rush Streets. Our investigation there is continuing, however, a near-surface fault has been uncovered. The recency of movement of this fault and how it fits into the tectonic framework of the region is still being reviewed.

The epicenter of the 1987 Whittier Narrows Earthquake and the main aftershock are both within one mile of the site. Most observers believe the main shock of the Whittier Narrows Earthquake occurred on a blind thrust fault known as the Elysian Park Thrust. The fault is called "Blind" because it is not exposed at the surface. Its presence is supported by seismic activity and geomorphic characteristics associated with compre.o;sional tectonics- anticlinal, folded hills (Reference 3). This blind thrust accommodates active compression occurring in the Los Angeles Region between the Transverse Range Province to the north and the Peninsula Range Province to the south. The seismic evidence suggests that the main aftershock of the Whittier Earthquake occurred on a right lateral strike slip fault. Whether the fault on which the aftershock occurred is the Whittier fault demonstrating active convergent right slip across the Whittier Narrows or simply a tear or break in the upper block of the Elysian Park Thrust is a point of contention. If the fault is an extension of the Whittier it would be capable of generating a significant earthquake. If the fault is a tear fault in the upper plate of the Elysian Park Thrust, it would only show displacement as a result of movement on the Blind Thrust (Reference 3).

Based upon our review, it does not appear that the scarp noled in FER-222 (Reference 6) transects the Angelus Avenue site. However, due to the proximity of the scarp and the poorly known character of faulting in the area, it was necessary to excavate a trench across the site to examine the subsurface conditions. The trench, excavated to a maximum depth of 15 feet, exposed artificial fill, historic stream channel deposits, buried topsoil and silty sand and gravely alluvial terrace deposits. The trench was mapped in detail to observe evidence of possible faulting. Displaced or offset sand or gravel deposits, displaced soil horizons. and features associated with liquefaction can all be associated with faulting. No evidence of faulting was observed in our excavation. Based upon mapping by Bullard and Lcttis (Reference 1) soil development on the alluvial terraces in the area of the Angelus Avenue site indicate a range in age from 13,000 to 70,000 years. At our nearby site at Delta and Rush, soils we believe to have a similar age range have been encountered. The log of our fault trench is included at the end of this report (Plate 1). The approximate location of the trench is depicted on Figure 1.

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LEIGHTON ANO ASSOCIATES, INC


2920024.02

No known active faults arc present al the site. As such, the principle seismic hazard which could affect the site is ground shaking resulting from an earthquake occurring along any of the major active or potentially active faults in Southern California. Figure C-1 in Appendix C shows the site location with respect lo the distribution of known major active and potentially active faults and the epicentral distribution of past earthquakes of magnitudes greater than 5.0 in the region (Appendix C). Appendix C shows a list of the faults in the area, their closest distance to the site and the magnitude of the maximum credible earthquake (MCE) for each fault. The major active and potentially active faults in the region that could produce or have produced significant ground shaking at the site include the Elysian Park Blind Thrust of the October 1, 1987 earthquake. The right lateral fault of the October 4, 1987 aftershock. Also in the region are the Raymond, Whillier, Santa Monica, Sierra Madre-Cucamonga and Hollywood faults.

The results of the deterministic seismic ground motion analysis are presented in Appendix C. The highest mean peak ground acceleration at the site is estimated to be 0.60g from a magnitude 7.0 earthquake on the Elysian park fault. The duration of ground shaking for this earthquake is estimated to be 25 seconds. The highest mean peak vertical ground acceleration at the site is estimated to be 0.83g from a magnitude 7.0 earthquake on the Elysian Park fault using the Campbell (1989) attenuation equation.

A probabilistic ground motion analysis was carried out based on Joyner and Boore's (1981), Campbell's (1988), and Idriss's (1987), attenuation equations, to determine the ground motion corresponding to 10 percent probability of being exceeded in 50 years as specified by the Unified Building Code. The results of the am1lysis presented in Appendix C indicates the maximum probable earthquake lo be 0.58g.

Strength Characteristics

One remolded and one undisturbed direct shear test was performed on representative soil samples to evaluate the strength characteristics of the recompacted and undisturbed soils. The cohesion and friction angle of the undisturbed soil was determined to be 100 psf and 40 degrees, respectively. The cohesion and friction angle of remolded soil was determined to be 100 psf and 33 degrees, respectively.

Consolidation Characteristics

A consolidation test was performed on a representative, undisturbed soil sample to evaluate the compressibility characteristics of the near-surface soils. The results of the consolidation test indicate that this soil has a low to moderate potential for consolidation.

LE/GH10N AND A!1$0CIATE$, INC.


2920024-02

Soluble Sulfates

Laboratory testing of representative soils revealed a low sulfate content. The potential for sulfate attack on concrete is expected to be low.

Resistivity and pH

Resistivity and pH test5 were performed on a representative near-surface soil sample. The results of the test indicate that the pH of this soil is 8.8 and the resistivity is 11,500 ohm-cm. These results indicate that ferrous metal components in contact with the near-surface soils have a low potential for corrosion.

Liquefaction Potential

Liquefaction is a seismic phenomenon in which loose, saturated, fine-grained granular soils temporarily behave similarly to a fluid when subjected to high intensity ground shaking. Liquefaction occurs when three general conditions exist: 1) shallow ground water, 2) low density silty or fine sandy soils, and 3) high intensity ground motion. Based on our conversation with the personnel from Los Angeles County Department of Public Works, Hydraulics-Water Conservation Records, we understand that the water table in the vicinity of the subject site is 70 feet below ground surface, However, ground water was encountered onsite at depths of 43 and 47 feet in our borings. To evaluate liquefaction potential, the ground water table at the site was assumed to be at an elevation five feet above that found during this investigation. The liquefaction analysis for the site was carried out using Seed's Simplified Method of analysis, and the ground motion corresponding to the "design" earthquake as defined by the Uniform Building Code as having a 10 percent probability of exceedcncc in 50 years. The results of the analysis indicate that the potential for liquefaction at the site soils is very low.

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LEIGH'ION ANO ASSOC/AllS, llVC.


2920024-02

CONCLUSIONS

General

Based on this investigation, it is our opinion that the proposed development is feasible from a geotechnical standpoint, provided the recommendations presented in this report are fully incorporated into the design and construction of the foundation. There appear to be no significant geotcchnical constraints onsite that cannot be mitigated by proper planning, design and sound construction practices. Specific conclusions are presented below:

• Due lo the proximity of the site to the Whittier fault and other faults in the Los Angeles region, the project site is expected to experience high levels of ground shaking from a regional seismic event within the projected life of the structure.

• Active traces of the Whittier Extension fault were not observed at the site.

• The potential damage due to liquefaction of lhe onsite soils is considered to be very low.

• The soil located approximately in lhc upper five feet onsite are considered moderately compressible. Overexcavation and recompaction of these soils should effectively reduce the potential for adverse settlement of the structure.

• Ground water was encountered al depths of 43 feet and 47 feet in Borings B-1 and B-2, respectively during our investigation. Ground water is not expected to be an adverse factor during construction.

• The near-surface soils are not expected to be excessively corrosive to ferrous metals.

• Damage to concrete in contact with the onsite soil due to soluble sulfate concentrations and alkalinity or acidity is expected to be negligible.

• All earth materials are expected to be readily excavated usmg conventional earthmoving equipment.

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2920024--02

RECOMMENDATIONS

All grading should be performed in accordance with the General Earthwork and Grading Specifications included in Appendix D unless specifically amended herein.

Site Preparation

Prior to construction, the site should be cleared of all vegetation, and debris. Efforts should be made to locate any existing utility lines. Those lines, if encountered, should be removed or rerouted if they interfere with the proposed construction. The resulting excavations should be properly backfilled and compacted. Debris, trash, or other organic material encountered during clearing, should be removed and disposed offsite.

Overexcavation and Recompaction

Since two options are being considered for the location of the foundation, recommendations are provided for the first floor parking structure to be located at the ground surface level and below ground surface (subterranean). To minimize the potential for adverse differential settlement, we recommend that the underlying subgrade soils be prepared in such a manner that uniform response of the soils to the applied loads is achieved, If the parking structure is to be at the ground surface, we recommend that overcxcavation and recompaction be completed to a depth of at least three feet below the elevation of the bottom of the proposed footings. The overexcavation and recompaction should extend to a minimum of three feet beyond the outside edges of the footings. Local conditions may be encountered which require deeper overexcavation. These areas are anticipated to be small and will be best determined during rough grading. Footing excavations along the west side of the structure may encounter fill (assumed uncontrolled) placed during the construction of the Alhambn1 Wash. Old fill was encountered during our fault trenching to within about 12 feet of the Alhambra Wash channel wall. If footings are to be constructed in this zone, all uncontrolled fill should be completely removed beneath the footings, extending outward at a 1:1 projection to firm competent material.

If a subterranean parking level is constructed, we recommend that the area below footings and slabs be processed a minimum of 12 inches below fooling elevation, and recompacted using a minimum standard of 90 percent of the maximum dry density as determined by ASTM Method D1557-78.

Parking areas outside the building footprint, access roads, and concrete slabs-on-grade should be overexcavated and recompacted to a depth of 18 inches prior to placement of base or concrete. After completion of overexcavation, the areas shnuld be scarified to a minimum depth of twelve inches, mnisture-conditioned, and recnmpacted using a minimum standard of 90 percent of the maximum dry density as determined by ASTM Test Method D1557-78.

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LEIGHTON AND ASSOC/ArES, INC,


2920024-02

Fill Placement and O">mpaction

The overexcavated soils are generally suitable for use as compacted structural fill, provided that they are free of organic material or debris. Any imported fill soil should be approved by the geotechnical engineer prior to importing. Imported fill should consist of clean soil with low expansion potential (preferably an Expansion Index of less than 20). All fill soils should be placed in thin, loose lifts, moisture-conditioned, as necessary, to near-optimum moisture content, and compacted using a minimum standard of 90 percent relative compaction as determined by ASTM Test Method D1557-78.

Foundation Design Recommendation

Either conventional cc>ntinuous or isolated spread footings founded on firm, competent material may be used to support the loads of the structure. Design recommendations are provided for the first floor parking level located on the ground surface (Option 1) and for the subterranean parking level located (Option 2). The following design parameters are recommended for the building foundation:

Continuous Footings:

Minimum Footing Depth: (below lowest adjacent grade)

Minimum Fooling Width:

Minimum Reinforcement:

Allowable Bearing Pressure: Allowable Bearing Pressure:

Sauare Footings:

Minimum Footing Depth: (below lowest adjacent grade)

Minimum Footing Width:

Minimum Reinforcement:

Allowable Bearing Pressure: Allowable Bearing Pressure:

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24 inches

18 inches

One No. 4 Rebar, top and bottom

2,400 psf (Option 1) 3,500 psf (Option 2)

24 inches

24 inches

No. 4 Rebars, 12 inches on center each way

2,500 psf (Option 1) 3,600 psf (Option 2)

LEIGHTON AND ASSOCIATE$, INC.


2920024-02

The recommended allowable bearing capacities can be increased by 500 psf per fool increase in foundation depth and hy 300 psf per font increase in foundation width lo maximum values of 4,500 psf and 5,000 psf for Option 1 and Option 2, respectively.

The allowable bearing pressures recommended above are for the combined total of dead load and live load. These values may be increased hy one-third for loadings of short duration, such as wind or seismic forces.

Total and differential settlement based on the above recommendations are anticipated to be less than one inch and one.half inch, respectively. It is our opinion that anticipated total and differential settlements are within generally accepted tolerances.

Retaining Wall Design Recommendations

Retaining walls should be designed using the following lateral earth pressure (equivalent fluid pressures). Values arc given for level backfill, using free-draining granular material. Should a variation in backl"ill material occur, these parameters should be reevaluated by the soil engineer.

Active Fluid Pressure:

At-Rest Condition:

Passive Equivalent Fluid Pressure:

Fluid Pressure Due to Seismic Loading:

Coefl"icient of Friction: (soil vs. concrete)

Allowable Bearing Capacity:

Depth of Retaining Wall Footing: (below lowest adjacent grade)

36 pcf (static loading)

54 pcf

400 pcf

35 pcf

0.35

2,500 psr

18 inches

The distribution of lateral earth pressure due to seismic lo;1ding has an inverted triangular shape. This force should be considered in addition to the appropriate lateral earth pressure under static loading conditions, when designing retaining walls under seismic loading conditions.

- 12 -

LEIGHTON ANO ASSOCIATES, INC.


2920024·02

The magnitude of lateral pressure on retaining walls depends on their freedom for lateral movement. If the wall is prevented from lateral movement at the top (i.e. basement walls), the horizontal pressure approaches the values of the at-rest condition, which should be used in the design. If the wall is unrestrained and allowed to move at least O.OOlH at the top of the wall, where H is lhe height of the wall, active pressure should be used in lhe wall design.

The total depth of retained earth for the design of cantilever walls should utilize the vertical distance helow the ground surface measured at the wall face for stem design or mea~ured at the heel of the footing for overturning and sliding.

During static analysis, if passive earth pressure and friction are combined to provide required resistance to lateral forces, the values of the static passive pressure should be reduced to two-thirds of the above value. The horizontal distance between foundation elements providing passive resistance should be a minimum of three times the depth of the clements to allow full development of these passive pressures.

All retaining structures should be provided with a subdrain system consisting of 4-inch diameter, perforated Schedule 40 PVC pipe, surrounded by a minimum of one cubic foot of a 1:1 mixture of washed concrete sand and pea gravel (or approved equivalent), per linear foot ofwalL The subdrain should flow at a minimum two percent gradient with the outlet directed to flow away from structures. In addition, a moisture barrier should be provided where moisture sensitive walls are anticipated.

The locations of proposed retaining walls, if any, should be reviewed by the soil engineer for remedial earthwork recommendations prior to construction.

Slahs-<m-Grade

Concrete slabs-on-grade should have a minimum nominal thickness of four inches or be designed for any special loads by the structural engineer. As a minimum, slabs should be reinforced with 6x6-W2.9xW2.9 welded wire fabric placed within the middle third of the slab. Where moisture sensitive flooring is planned, we recommend placing a 10-mil Visqueen moisture barrier beneath the slab. The moisture barrier should be underlain by a minimum of four inches of clean sand, and covered with a minimum of two inches of clean sand.

To further reduce the potential for moisture migration through slabs-on-grade, we recommend a surface sealant be applied by a qualified flooring contractor prior to placing moisture sensitive flooring.

LEIGHrDN AND ASSOCIATES, INC.


2920024-02

Slabs-on-grade generally have large surface areas from which excessive evaporation can occur from the top surface while the bottom surface is restrained from moisture loss. This uneven evaporation causes drying shrinkage of the top surface (curling of slabs) and resultant cracking. Most of the commercially available curing compounds are effective if the manufacturer's recommendations are doubled, applying a second coat right after the first coat has lost its sheen. In addition to, or instead of using curing compound, if the concrete pour is kepi moist during the first three to seven days (frequenlly sprinkled or covered by wet burlap), there would be less drying shrinkage and cracks.

Installation of weakened plane joints is an effective method of controlling shrinkage cracks. If they are installed deep and early enough, and at a sufficiently close spacing, the shrinkage cracks would occur at the joints and unsightly, random cracking is avoided or at least reduced. To be effective, the minimum recommended depth of joints is one-third the thickness of the flatwork. Therefore, for a 4-inch thick walkway or patio slab, an effective joint needs to be a minimum of 1-1/3 inches deep, and for a 6-inch thick driveway, the depth needs to be two inches. Scoring tools can seldom achieve this depth and saw-cutting is normally used. If conventional saw-cutting is planned, it is imperative to keep the concrete surface wet until the saw-cutting has been completed, preferably with less than 24 hours of the pour. Alternatively, "Soft Cut" techniques can be used to form the joints within !he first few hours of the concrete pour. In-filling contraction joints with a flexible joint filler also enhances long-term performance of !latwork. Where lateral extent of !latwork exceeds 80 to 100 feet, inclusion of expansion joint (full depth, one-half inch wide joints, filled with felt and topped with mastic) is recommended.

Cement Type

The soluble sulfate testing of the representative onsite materials indicates that the materials exhibit a low potential for sulfate attack on concrete. A:; such, common Type II cement is considered to be suitable for use in concrete construction of this site.

Temporary Construction &cavatinns

All temporary excavations for the basement parking structure should be in accordance with the current OSHA requirement•. All excavations greater than five feet should be either shored or laid back at a 1:1 slope, before personnel are allowed to enter.

IEIGKTON AND ASSOCIATES, INC.


2920024-02

Trench Backfill

Trench excavations for utility pipes may be backfilled with onsite soils under the observation of the gcotechnical engineer. After the utility pipe has been laid, the space under and around the pipe should he backfilled with clean, granular soil, having a sand equivalent of 30 or greater, to a depth of least one foot over the top of the pipe and water-densified in-place in a contmlled manner, before the controlled backfill is placed.

Drainage and Irrigation

Surface drainage should be designed by qualified personnel. As a minimum, it should be directed away from foundations and toward approved drainage devices. Irrigation of landscaping should be controlled to maintain, as much as possible, a consistent moisture content sufficient to provide healthy plant growth without overwatering.

Geotechnical Testing and Observation

Our geotechnical recommendations provided in this report arc based on preliminary design information and subsurface conditions as interpreted from limited exploratory borings. The geotcchnical consultant should review the grading plans and/or construction plan when it becomes available and comment on the geotechnical aspects of the project. Our preliminary conclusions and recommendations presented in this report should he reviewed, verified and revised accordingly, when grading and building plans are available and again during site grading.

The geotechnical consultant should provide observation and testing during construction of the development. The consultant should prepare a final geotcchnical report summarizing the conditions encountered and any field modifications to the recommendations provided herein. Geotechnical observation and testing should be provided:

• After completion of site clearing.

• During removal and overexcavation operations.

• During compaction of fill materials.

• After excavations of all footings, prior to placement of reinforcing steel and concrete.

• During retaining wall backfilling.

• During utility trench excavation, backfilling and compaction.

• When any unusual conditions are encountered.

- 15 -

LEIGHTON AND ASSOC/Am, INC.


2920024-02

We appreciate this opportunity to have been of service to you. If you have any questions regarding this report, please call our office at your convenience.

CY /DCS/PB/rsh

Distribution: ( 4) Addressee

Respectfully submitted,

LEIGIITON AND ASSOCIATES, INC.

~U,;15 Project Geologist

~r:-r<f~ -David C. Smith, R.C.E. 46222 Project Engineer

- 16 -


I I I I I I I I I

•• I I I I I I I I I

ANGELES AVENUE

-------/ I

l

8-1~

BORING AND TRENCH LOCATION MAP,

PROPOSED SENIOR CITIZENS APARTMENTS, CITY OF ROSEMEAD,

LOS ANGELES COUNTY, CALIFORNIA L.....~~- -~~-~~-~~~~~~~~~~~~~~~~~~~~~~~~-

LEGEND

B-2~

I __ ......,t-z-=-=:s:-1

APPROXIMATE BORING LOCAT\ON

APPROX!MATE FAULT TRENCH

LOCATION

I Project No. 2 9 2 00 24-0 2 I Scale Not To S c a I e 1 PB ' Engr./GeoL --~-=------~ Drafted By ___ .I_,, a'-"h'-----

ij Date 4/ ·1 I 9 3

~n·.ifl I ' .1 u I lLLU Figure No. 1


GEOTECHNICAL BORING LOG B-1 Date -----'2=--_,l'--'l'---~9-"3 ___ _ Sheet 1 of 2 Project ----------"'R"'o""se,,,m=ea:.d::....!A.!Jp"'a"'r"'tm=e"'u"'ts,__________ Project No. --'2"'9'"'2"'0'"'0~2~4~-~0~2 __ Drilling Co. _________ _,,2_-_,_,R--'D=rl"-'11"-'in,,.g.,,_,I,,,,n"'c_________ Type of Rig __ C~M=E~S~S __ Hole Diameter 8" Drive Weight ______ _:l'-'4'-'0'--'-'lb'-'--'A=u"-'to'-'m"'a"-t'"i=.c _______ Drop 30 m

·Elevation Top of Hole Ref or Datum

c 0 ...... ..... •• ~ ..

.... "'

.c..., ... "-• ,!lo.

0

u ·• .c D1 "- 0 O..J L

"' . :-:. . . ', _ _.

. : '

- ·:.

10-. ·,:.

- .

. ' .. . •.

': ' . . •.

-

15-:- ..

-

- ... · ..

. . . . ' . . .

20-

-':'

-

. '. -

. ·.· .. 25-.

-

--

- .

--SOSA( 11/77)

• • 'C J .. ·• .. ..

<C

D z • .n • , .... .... "-

I

2

• • "'

SPT

3

SPT

h

12

19

JI L c

:< • L ' J .. .., c •• .• .., DC I: D

"

103,& 18.1

118.0 1&.2

-~ . ' . "' .... ' "~ .... ., ·• . o" ., ~

SM

CL

SM

38 11&.8 16.3 SM

26 SM

82 112.2 13.o SM

GEOTECHNICAL DESCRIPTION

Logged By ---------"C"'Y'----------Sampled By CY

2': SILTY SAND 1 trace of fine gravel, fine rralnwd, brownt moiat.1 loose to medium dense

5': SANDY CLAY 1 alight1y plastic, fine grained sand, reddilh brown with oxidir.:ed stain11o, very moist, firm

10': SILTY SANO, mixed with gravel, gravel 1i1c111 to 1 inch, fine to C.Oil.ne grained, brown, moist, medium dentej inte['bedded with thin layer of •~ndy •lit

15': SILTY SAND 1 !!!lightly tnice.ceous, very fine gTained, liiht brown with oxidized iit~ins, moi!t, very firm

20 1: SILTY SAND, Vliry fine gra.ined 1 brown with oxidiir.ed stains, :rnoist, medium d41nB-e

'5': SILTY SAND, very fine grained, brown with oxidiicd "tains, moi:!;t 1 dense

LEIGHTON & ASSOCIATES

I GEOTECHNICAL BORING LOG 8-1

I Date ---=2--1~1~-~9~3 __ _ Sheet 2 of 2

Project ---------~R"'o,,_$e,,,m=•:o:ad,,_,A.:Jp"'a"'r"'t"'m"'e"'n"'ts'------------ Project No. --'2"'9'"'2~0~0~2~4~-~0~2 __ Drilling Co. _________ _,,2c:.·~Rc.,D=ri'-"il'-"ln,,,g.,,'--'I'-'n"'cc...... _______ ~- Type of Rig __ C"''""'ME~S~S __ Hole Diameter 8" Drive Weight ______ ___,1'-'4'-"0:....:.:lb,_,_,A=u,,toc:m:::a=.t:.:i=.c _______ Drop 30 m Elevation Top of Hole Ref or Datum I

:J " ,;~ c • 0 ... ... • GEOTECHNICAL DESCRIPTION 0 u • ·• • • z •" L •" ..... .i::.., ·• .,, • • ,..,

.<:: " ' • 0 ci.. .... ... . .... .ll. o"- ... c u~ • • n.. n.o ... , ... • u •• ,._ g .. O.J ·• ... n. -< L 0 n. ..... ... " • L ... E " . oc Logged By CY ... CJ ... • n. C' "0 •-I ::i Ill 0:

" u ell- Sampled By CY 0

I I

so ·' SPT ., SM !0': SILTY SAND, fine to m.edh..an grained, brown with oxidii:ed stains, . '. .. m.obt.1 medium deruie; - ·'

',· .. (W :a.ter on aample:r; no water wa.a observed in the hole) ·'.

-· I . '.

'. " - ' ·.:·

-· - . ,. I - .

S5-,.

" - .. - . SS 1: SILTY SAND 1 fine grained, light brown with ox.idi!ed 111tain1

1 1li.s;htly - - 6 •• !)LI 26.Q SM

moi11t, denr.e; liiht brown, non plastic sandy silt at bottom 0£ :aampler

' I - "

-· - . I -

" . ·.· .. ,.

40-·, '. -. -SPT 67 SM 4.0': SILTY SAND, mixed with gravel 1 gravel l!:izea to 3/4-ineh, fine to .....

coarse gra.ined, brown to reddish brown, slightly moist, dense - ,·. •" . ' I -· ·,· ..

~ ~

' . ·.· ..

-<' ·'. • ~ " ' .. '·'. I ·.· .. -

- --45~:

4.D': SILTY SAND, mi.xed with gravel1 gravel aizea to 3/4·inch1 fine to " .. " 62 113.:Z 2.4 SM

< - . For 6" co11.nt grained, brown to reddish brown, 1lightly moist, dense

" I

< . - . - ,,·, " - :- ·-·:-·. I

. ' . -

- '. -. ',· ..

50-50t: SILTY SAND, fine grained, brown, very moist, dense " . - SPT 44 SM I

- . '

I --

I -

&5-Total Depth = 61.6 feet Ground water at 43 feet - C:ii.ving: ra.t 4.2 feet Backfilled with native material.

-I -

I -

""

I 505A(11/77) LEIGHTON & ASSOC IA TES

I GEOTECHNICAL BORING LOG B-2

I Date ___ _,,2,_-.=-1~1-~9~3'----- Sheet 1 of 2 Project _________ ....::;R:.::o.::.se"'m=ea::.d::;....;A~p"'a"'r-'tm=e"'n"'ts=---------- Project No. --'2"'9'-'2'-'0'-'0~2'-4'---'0.::2 __ Drilling Co. _________ .::2_-:;R'-"'D=ri~ll""in~g~,-'I"'n:.::c_________ Type of Rig __ C=cM=E~5-~5 __ Hole Diameter 8" Drive Weight ______ __,1:.::4:.::0c..:..:lb"-'A=ut:.:o!!m:::;a:.l::i::.c _______ Drop 1.Q_ 10

Elevation Top of Hole Ref or Datum I • JI x i~ c • D .. .. • GEOTECHNICAL DESCRIPTION D 0 • "" • • ::: .D L • •"' '"" .i:., '" -g • • , .. ... ... .I: DI .D • 3D er,.. .. c .....

•• II.. 11.0 .. J-< olL • u •• o<! 'IL

,!l IL ... '" 0-11. -< L c II. """ _,., L .. E ID m DC Logged By CY .... CJ .. • II. JI 1: D ·"4~

UJ « ., L u Jl~ Sampled By CY c

I I

0

- .. ': . aag·l . • .

. •. 21

: SILTY SANO, fine to eoane ;rained, brown, 11iihtly moh1t, medium ... 7 14 llS.2 S.2 SM

- .. d•n••i da.rk brown BiHy et1.nd a.bove 2 feet ':' ..

>- >-

I I

5-SPT 9 CL 51

: SANDY CLAY, slis:htly plastic, fine to medium ,rained sand, brown

- with oxidized l!ltain:111 moil8t 1 firm

" I - .. ...

r.

I .. .. - .. ...

10~·

a >IL/S~ 10': SANDY SILT, non pla11tic, very fine graln~d, brown, 18lightly moist, H 12S.O 10.1 - . stiffi mixed with fine grained, brown 1 11ilty sand I -'

I - >- -

15-SPT 26 SM 15': SILTY SAND I finifl t.o l::OM"Ioe 1ralncd, ~rac.111 or gravel, 15.ligh~ly ...

cemented, brown with oxidiie eta.ins, elightly moi~t, mectium dense -I

.. - .. >- ~ . . . - · .. I _._ ..

.. 20-:- .. 9 98 120.5 2.4 SM 20 1

: SILTY SAND, mixed with gravel, gravel sizes to l/2~inc.h, fine to

- > c.oane r;:ra.ined, brown to reddish brown with gray and white 11:ravel, >-damp 1 dtn&t1 ..

-· >- >-

I I ... _,

-1 · : :··.·

25- -:i .. .. SPT 83 SM 25': SILTY SAND, mixed with gravel, gravel siz.es to 2/4-inc.h, fine to ..

c.o:a.r1Je ,rrained, brown to reddish brown with gray <i.hd white gravel 1 -(: damp1 densei Pockets of sandy silt

. - .·

I I

-...

-· I

... I I 505A( 11/77) LEIGHTON & ASSOC IA TES


I I

·Date ___ ...:2:....--"l.:.l-'-9'-'3'----- Sheet 2 of 2 Project ---=--------~Ro::o::.••::.:m=e,,_ad"=-'A-"p"'a::.:r_ot:=m:=e_,,n"'ts'------------- Project No. --'2"'9:..:2::.:0:..:0:.:2:..:4'--_,,0.,,2 __ Drilling Co. ---------=-2---'R:.:_:Docr:.ol;;.:11;;.:ln,,.g..,_,~Ic.::n::.c_________ Type of Rig __ C::.M=E'-"-5"----5-Hole Diameter 8" Drive Weight ______ _,1"'4"'0'-1'-'b'-'--'A'-'u=to,_,m"'a::.t,,_1::.c ------- Drop 30 ; n Elevation Top of Hole Ref or Datum

I I

JI

"' ui ~ c • Q .. .. • GEOTECHNICAL DESCRIPTION Q u • ... • • :z: .c L •"' ... .c .. ... " • • , .. ..... .C OI J ,c CL .... . •• ... D-0 ... nm olL • u .., c o~ "-• J-< •• :> • ~IL m_J ... -< L c "-o IL L .., ,_ "- ..... .... .,

E m• oc Logged By CY .... " .. • II. :I ro ·~:i w « "' L 0 £v CY c Sampled By

30 10 87 Q6.Q 17.7 SM 30': SILTY SAND, fine gre.ined 1 brown, 11i;:htly moist, dense

I --: . ,. ..

-:1: :· - .. . '. . . . .

I -·:: :' .. ':' -·

'' '·.·

I 36-

SPT 27 oM/M 35': SILTY SAND 1 mixed with sandy silt1 very fine grained, brown 1 tnoist1

- medium dense ':' .. - ..

I ':'

- .. . : ' ..

-

I 40-

.. ·, -: '.·

11 gg ll3.l 4.2 SM 40': SILTY SA.ND, mixed wit.h gravel, ;;ravel sizes to 1-ini;:;h, fine to coarse - - grained, brown with oxidized staln:s, :slightly mois.t, very den~t

- :-

I - .

- .' ·,:' . ' f-

I 45-SPT 78 SM 4.5': SILTY SAND, mixed wnh gravel, ;-r~vel sil~es to 3/4-inc.h

1 fine to

:1.": . eoarse grained, brown with oxi.dir;ed stains, slightly m.oi"t, very dense - ..

I ' :: : :·

- f-,.

- 1·,: f-

-

I 60-< ·,:.

12 93 119.1 12.5 SM 50'; SILTY SAND, mixed with gravel, gravel 11iies to 3/4-inch, fine to

- c.oarse gra.in111d 1 brown with oxidized stains~ !!lightly moist, very den::;t

I -

-

I - \.

55- .. 'total depth = 51.5 feet

I - Ground woitier ;!l.t -'i teet .. Caving at ~e feet

Ba<::kfilled with native material. -

-

I -

I SOSA( 11 /77) LEIGHTON & ASSOC IA TES


GRAUEL SANO

bDARSE ~OARsa SILT OR CLAY

FINE MEDIUM FINE

SIEUE OPENING SIEUE NUMBER HYDROMETER 1" 3.1.:i;l:" • e 16 30 68 190 200

1"0

ee "'~ I\ ~

60 \

f-:i: L

"' 70 ....

\\ lU ::>

>-"' 60

\ "' z .... "' 60

"' ~ <I c. f-

40 z lU u [!'. lU c. 30

20

10

0 10 1 0.1 0.01 0.001

PARTICLE DIAMETER IN MILLIMETERS

Symbol Boring Sample Sample Depth Field Soil Type Number Number (feet) Moisture (%)

0 B-l 3 15.0 16.3 SM

1%1 B-2 8 10.0 10.l ML/SM

Project No. 2220024-!!2 GRAIN SIZE DISTRIDUTION CURVE Project Name Bo~~m~aa Aua:rtm~ntri D:J[D

Date 4/1/93 Figure No . .Jt:L


1::19 . . \

. 1as

' •

/ ~ '·. 1a• '-&

' ' ~

' ... 116 u II. ~ ' ,.. ... H

"' 110 z IU 0 ,.. "' 0

106

100

96

90 0 6 10 16

MOISTURE CONTENT

Symbol Boring Depth Soil Description Number (feet)

0 B-1 1.0 Brown Silty Sand, tr/Gr

Project No.

MAXIMUM DENSITY TEST Project Name

Date 4/1/93

109>< Saturati on Lin•

Sp cif'ic cro-.vi ~u • 2.7e

. \ .

' . \ .

'\ .

' '

' . '

... as "" ( Y.>

Optimum Maximum Dry Moisture (%) Density (pcf)

10.5 123.0

222!lQ2g-Q2

Bosi:mtAd Agaclm~nts Cf]CTJ Figure No. B-2


2500

2000 /. ~ / ... It 1600

/ v

01

m / It ... 01

It <I !!! 1000

/ 01

v sea /

/ /

/ /

v a • 500 l.BB~ 1600 200e 2500

NORMAL STRIOSS Cp"f'l

Boring No. B-2 Before Test:

Sample No. II Dry Density (psf) 1:u.J Depth (ft) l!!!! Moisture Content (%): 13 s Soil Type ML[SM

Type of Sample Brown Sandy SllUSllty Sand

Friction Angle (deg.) 40,0

Cohesion (psf) IO!!.!.!

Project No. 222!!!!24-!.!2

DIRECT SHEAR Project Name Bo~~m~ad Anartm~nt~ mm Date 4/1/93 Figure No. B-3


2600

2000

~

,,('

~ 1600 v y

"' / "' Ill

"' I-

"' ~ _, Ill 1000

/ J:

"'

/ 600

I _t;;r

/ / _,

;~ /

0 0 600 1909 1690 2000 2500

NORMAL STRESS (p•O

Boring No. B-1 Before Test:

Sample No. Bag-1 Dry Density (psf) 110.6

Depth (ft) 1.0 Moisture Content (%): 16.5

Soil Type

Type of SampBrown Silty Sand Remolded to 90% R.C.

Friction Angle (deg.) JJ.!l Cohesion (psf) l !l!l !l

Project No. 2~;?QQZ:!l-!l~

DIRECT SHEAR Project Name RQ~~me~!! A1,rnrtm~11t~ [][TI Date 4/1/93 Figure No. _B-4


e

~ 1

• r----.._"' • • c

"' 2 0

~ ·~ r. ......... ....

• " .... ._ )II', n. ,._ ,_ • --~ r-, • -"' 4

~ ... 0

• .., B c • u

c m

11. 6 v

z 0 .... .... .., <I 0 .... .J 0 B

"' z 8

a

10 0.1 1 a

VERTICAL STRESS ( ksf"l

LEGEND: 0 At Field Moisture

• After Addition of Water

Boring No. B-1 Initial Dry Density (pcf) 112.6

Sample No. 2 Moisture Content (%):

Depth (ft) 5,0 Before I •;,Q

Soil Type CL After 14,5

Soil Description Sandy Clay

Project No. 222QQ24-Q2

CONSOLIDATION CURVE Project Name Bos!:ID!:ild Anartm~nt!i aJDJ Date 4/1/93 Figure No. B-5


Boring/ Soluble Compacted Compacted Dry Depth (ft) Sulfate Moisture Density

(%) (%) (pcf)

B-2 0.1 1.0

EXPANSION INDEX AND SOLUBLE SULFATE

TEST RESULTS

Final Volumetric Expansion Expansive Moisture Swell Index Classification

(%) (%)

Project No: 2920024-02

Project Name: Rosemead Apartments

Date: 4/1/93 Figure No.: B-6

UJ Cl ::l I.... Ice _J

35.00

34.33

33.55

33.00

EP NTRAL LOCATION OF EARTHQUAKES WITH 5.0 < M, 1000-1991

g

119.00

LONGITUDE

M • 7

0 M • 6

Q) 0

M • 5

* SITE

~

'

.... I

u

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

35.00 FAULTS

111 SAN ANDREAS \C

~~ 2 SAN ANDREAS 1'

13 SAN ANDREAS l'

~ 4 SAN ANDREAS (

i) 5 SUPERSTITION 6 CAMP PENDEL TC 7 ROSE CANYON B SAN CLEMENTE

~ 9 PALOS VERDES

~ 10! ELSINORE-A 11 ELSINORE -C !2 f'iHITTIER

~ /--....'---- 13 NEWPORT INGLE

34.33 14! NEWPORT INGLE 15 SANTA MONICA

-----------~ ~~9) 16) BANNING 17 MALIBU COAST 18 RAYMOND

UJ ,? ~J-~2&} 19 SIERRA MADRE-

0 20 CUCAMONGA :::> 21 SAN JAC I NTD {l I- 122 SAfj JACINTO ( H ~J 23 SAN JACINTO f I-..c ) .RV 124 SAN JACINTO [ N ....l ~25 SM! JACINTO E I

26 SAN JACINTO E u 27 SANTA SUSANA

4) 28 SM< GABRIEL-I

33.66 (iO) \29J 5AN GABRIEL-E 30 CAMPROCK

~ p 11 GARLOCK 32 CORONADO BANo

~ (33 SAN JOSE

2~ CITIES -

RV: AJVERSIDE

~) LA: LnS ANGELES

~) OS YB: YORBA LINDA

{32)~ If Es SA: SANTA ANA

(i 1) OS: OCEANSIDE ; ~) ES· ESCONOIO°=

33.00 1i9.00 1i7.B3 116.66 115¥0'

COAST

SITE

LONGITUDE

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

I I

I I I

X: MCE: Tr: HPGA: VPGA: D:

Shortest distance from the site to the fault in km Magnitude of the Maximum Credible earthquake The expected return period for the Maximum Credible earthquake Horizontal peak ground acceleration Verical peak ground acceleration Expected duration in seconds

X MCE Tr HPGA VPGA D km Years g g SEC

1---:-[;;~1;~-p~;k·------------------------0·-·1:0·---;-----:60----:93··25·---

I I I I I I I I I I I

* RAYMOND 6 6.7 3000 .39 .37 21 *WHITTIER 10 7.3 730 .38 .36 31 * SANTA MONICA 8 6.7 3960 .35 .32 21 * SIERRA MADRE-C 12 6.5 5000 .24 .18 19

HOLLYWOOD 11 6. 4 1630 . 24 .18 18 *SIERRA MADRE-D 13 6.4 5000 .22 .16 18 *SIERRA MADRE-B 18 6.5 5000 .17 .12 19

VERDUGO 20 6.7 ? .18 .12 21 SAN JOSE 21 6.7 ? .17 .11 21 SA/(Mojave+S.B.+Coachella) 48 8.0 210 .15 .12 50 SA/(Mojave+San Bernandino) 48 7.8 160 .13 .10 44 NEWPORT JNGLEWOOD-B 25 6.8 1450 .15 .10 22 NEWPORT INGLEWOOD-A 28 6.9 1650 .14 .09 24

*SIERRA MADRE-A 21 6.4 5000 .14 .09 18 SAN ANDREAS(MOJAVE) 48 7.5 160 .11 .08 35 SA/(Coachella+San Bernandino) 60 7.8 260 .10 .08 44

*SIERRA MADRE-E 25 6.4 5000 .12 .07 18

C-3

I I I

X MCE Tr HPGA km Years g

VPGA D g SEC

SAN ANDREAS(CARRIZO) 73 8.0 300 .09 .07 50 PALOS VERDES 38 7. 0 2900 .11 . 07 25

*SANTA SUSANA 36 6.9 630 .11 .07 24 ·-----------------------------------------------------------------------------

*Expected reverse/oblique faulting mechanisms

I It has been reported that earthquakes with reverse/oblique faulting mechanisms could generate higher PGA than earthquakes with strike-slip or normal faulting mechanisms. However, the phenomena depends upon

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

the rupture direction with respect to the site among other things. The issue is actively being investigated by seismologists.

The HPGA values are the mean of three HPGA values estimated based on attenuation equations by Campbell (1988), Idriss (1987), and Joyner and Boore (1981).

The VPGA values are based on Campbell (19B9) attenuation equation.

Duration is based on interpretation of the work by Dobry (1978) and Trifunac (1975).

Return period for MCEs are based on faults slip rates.

SEISMIC DESIGN PARAMETERS *****************************

The design peak horizonal ground acceleration at the site based on MCE is estimated as .60 g. This ground motion is due to an earthquake of magnitude 7.0 on the Elysian Park Thrust fault at an epicentral distance of 0 km. The duration of ground shaking for this earthquake is estimated as 25 seconds.

The expected maximum ground shaking duration at this site is 50 seconds due to an earthquake of magnitude 8.0 on the SA/(Mojave+S.B.+Coachella) fault at an epicentral distance of 48 km. The peak acceleration for this earthquake is estimated as .JS g.

C-4

~---~----------------------------------------·----------------------------I MPE: Lower Bound Magnitude with 480-Year Return Period ( .21 % Annual Risk)

MCE: Maximum Credible Earthquake T: Expected Mean Return Period

.Slip Rate: Fault Slip Rate, Wesnousky (1986)

List of the Faults Considered for this Analysis

fault MPE MCE Slip Rate T mm/Yr Years

I 1 SAN ANDREAS(CARRIZO) 8.0 8.0 34.0 296 2 SAN ANDREAS(COACHELLA+S.B. Mnts) 7.8 7.8 24.0 256 3 SAN ANDREAS(MOJAVE) 7.5 7.5 30.0 162

I 4 CAMP PEND EL TON 5.6 7.0 1.2 1050 5 PALOS VERDES 5.3 7.0 .7 2900 6 ELSINORE-A 6.0 7 .1 4.0 550 7 WHITTIER 6.1 7.3 4.0 730

I 8 NEWPORT INGLEWOOD-B 5.3 6.8 1.0 1450 9 NEWPORT INGLEWOOD-A 5.3 6.9 1. 9 1650

10 .SANTA MONICA < 4.5 6.7 .3 3950

111 BANNING 7.0 7.0 ? 300 12 RAYMOND 4.7 6.7 .2 3000 13 OAKRIDGE 5.9 6.9 3.5 520

114 SAN FERNANDO 6.5 6.5 ? 200 15 SIERRA MADRE-A < 4.5 6.4 ? 5000 16 SIERRA MADRE-8 < 4.5 6.5 4.0 5000 17 SIERRA MADRE-C < 4.5 6.5 ? 5000 118 SIERRA MADRE-D < 4.5 6.4 ? 5000 19 SIERRA MADRE-E < 4.5 6.4 ? 5000 20 CUCAMONGA 5.4 6.6 6.4 700

121 SAN JACINTO(LYTLE CREEK-CLAREMONT) 7.0 7.0 10.0 107 22 SANTA SUSANA 5.8 6.9 4.5 630 23 SAN CAYETANO 7.1 7.1 5.0 430 24 SAN GABRIEL-A 5.9 7.0 5.0 560

12s SAN GABRIEL-8 6.7 6.7 5.0 400 26 HOLLYWOOD 4.8 6.4 .8 1630 27 VERDUGO 5.1 6.7 ? 1500

128 SIMI 5.6 6.8 ? 700 ------~~-----------------~---------------------------------------~------

I Peak Ground Accelerations *************************

I Probability% for PGA to be 10 Exceeded in 50 Years Annual Risk% . 21

----WM------------------------------------~-----------------~------------

I I I I

PGA-H (g): CAMPBELL (1988) PGA-H (g): JOYNER & BOORE (1981) PGA-H (g): IDRISS (1987)

.64

.59

.52

C-5


1.0

2920024-02

APPENDIXD

General Earthwork and Grading Specifications

General Intent

These specifications present general procedures and requirements for grading and earthwork as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, and excavations. The recommendations contained in the geotechnical report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geoteehnical report.

2.0 Earthwork Observation und Testing

3.0

Prior to the commencement o[ grading, a qualified geotechnical consultant (soils engineer and engineering geologist; and their representatives) shall be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It will be necessary that the consultant provide adequate testing and observation so that he may determine that the work was accomplished as specified. It shall be the responsibility of the contractor to assist the consultant and keep him appraised of work schedules and changes so that he may schedule his personnel accordingly.

It shall be the sole responsibility of the contractor to prnvide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If, in Lhe opinion of the consultant, unsatisfactory conditions, such as questionahle soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions arc rectified.

Maximum dry density tests used to determine Lhe degree or compaction will be performed in accordance with the American Society for Testing and Materials test method ASTh101557-78,

Preparation of Areas to be Filled

3.l Clearing und Grubbinl!: A.II brush, removed or piled and otherwise disposed or.

vegetation and debris shall be


2920024-02

3.2 Processing: The existing ground which is determined to be satisfactory for support of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory shall be overexcavated as specified in the following section. Scarification shall continue until the soils arc broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction.

3.3 Overexcovution: Soft, dry, spongy, highly fractured or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, shall be overexcavated down to firm ground and approved by the consultant.

3.4 Moisture Conditioning: Overexcavated and processed soils shall be watered, dried-back, blended, and/or mixed, as required to attain a uniform moisture content near optimum.

3.5 Recompaction: Overexcavated and processed soils which have been properly mixed and moisture-conditioned shall be recompacted to a minimum relative compaction of 90 percent.

3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be stepped or benched. The lowest bench shall be a minimum of 15 feet wide, shall be at least 2 feet deep, shall expose firm materials, and shall be approved by the consultant. Other benches shall be excavated in firm materials for a minimum width of 4 feet. Ground sloping flatter than 5:1 shall be benched or otherwise overexcavated when considered necessary by the consultant.

3. 7 Approval: All areas to receive fill, including processed areas, removal areas and loc:-offill benches shall be approved by the consultant prior to fill placement.

4.0 Fill Material

4.1 General: Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant. Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by the consultant or shall be mixed with othc:r soils to sc:rve as satisfactory fill material.

4.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 12 inches, shall not be buried or placed in fills, unless the location, materials, and disposal methods arc specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 feet vertically of finish grade or within the rnnge of future utilities or underground construction, unless specifically approved by the consultant.


2920024-02

4.3 Import: If importing of fill material is required for grading, the import malerial shalJ meet the requirements of Section 4.1.

5.0 Fill Placement and Compaction

5.1 Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 inches in compacted thickness. The consullant may approve thicker lifts if testing indicates the grading procedures arc such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformily of material and moisture in each layer.

5.2 Hll Moisture: Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or shall be blended with drier material. Moisture-conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content al or near optimum.

5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned, and mixed, it shall be uniformly compacted to not less than 90 percent of maximum dry density. Compaction equipment shall be adequaicly sized and shall be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree of compaction.

5.4 Fill Slopes: Compacting of slopes shall be accomplished, in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at frequent increments of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope shall be at least 90 percent.

5.5 Compaction Testing: Field tests to check the fill moisture and degree or compaction will be performed by the consultant. The location and frequency of tests shall be at the consultant's discretion. In general, the tests will be taken at an interval not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of embankment.

6.0 Subdruin lnstullntion

Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials shall not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. All subdrains should be surveyed for line and grade after installation and sumcient time shall be allowed for the surveys, prior to commencement of filling over the suhdrains.

D-3


2920024-02

7.0 Excavation

Excavations and cut slopes will be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas shall be performed, and/or remedial grading of cut slopes shall be performed. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the consultant prior to placement of materials for construction of the fill portion of the slope.

D-4


2920024-02

APPENDIXE

References

1. Bullard, T. F. and Lettis, W. R., 1992, Quaternary Geologic and Tectonic Geomorphic Investigations in the Whittier Narrows Area, Los Angeles Basin, California in: Proceedings of the 35lh Annual Meeting, Association of Engineering Geologists, 1992, Martin L. Stout, ed.

2 California Division of Mines and Geology, 1991, A Special Studies Zones Map, El Monte Quadrangle Revised Official Map Effective November 1, 1991.

3. Davis, T. L., Namson, J., and Yerkes, R. F., 1989, A Cross-Section of the Los Angeles Area: Seismically Active Fold and Thrust Bell, 1987, Whittier Narrows Earthquake and Earthquake Hazard: Journal of Geophysical Research, v. 94, No. 87, p. 96-44-%64.

4. Hart E. W., 1992, Fault Rupture Hazard Zones in California, California Department of Conservation Division of Mines and Geology Special Publication 42, Revision 1992, 32 p.

5. Lamar, D. L., 1992, Whittier Elsinore Fault System, Southern California: in Engineering Geology Practice in Southern California B. W. P. pkin, R. J. Proctor eds. p. 255-267.

6. Treiman, J. A, 1991, CDMG, Fault Evaluation Report FER-222, Whittier Fault Zone, Los Angeles and Orange Counties, California.

Aerial Photographs

Date Flight Frame Scale Source

1929 C300 K323 1:18,000 Fairchild K324

07-02-38 AXS 58-88 1:24,000 USDA 58-89

09-16-41 7401 11. 12 1:24,000 Fairchild

10-19-53 AX5-13K 180, 181 1:20,000 USDA

. . '• -

OVERSIZED -·-·. -. DOCUMENT HAS

BEEN PULLED AND SCANNED WITH THE MAP

FILE. ··---__

·~

·- .

.

' . . -. -

'

- . -. . . - . . .

....


LEIGHTON AND ASSOCIATEt INC. Geotechnlcal and Environmental Engineering Consultants

RESPONSE TO PRELIMINARY REVIEW OF GEOTECHNICAL REPORT FOR 'I1IE PROPOSED SENIOR CTTIZENS HOUSING

COMPLEX, ANGELUS A VENUE, CITY OF ROSEMEAD, CALIFORNIA

February 15, 1994


Prepared For:

CITY OF ROSEMEAD 8838 East Valley Boulevard Rosemead, California 91770

1470 SOUTH VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765 [909) 860·7772 • 1800) 777· 2286 FAX (909) 860· 1089


To:

Attention:

Subject:

Reference:

LEIGHTON AND ASSOCIATES, INC. Geoteehnieal and Environmental Engineering Consultcints

February 15, 1994

City of Rosemead 8838 East Valley Boulevard Rosemead, California 91770

Mr. Peter Lyons


Response to Preliminary Review of Geotechnical Report for the Proposed Senior Citizens Housing Complex, Angelus Avenue, City of Rosemead, California

(a) Leighton and Associates, Inc., 1993, Preliminary Geotechnical and Fault Investigation for the Proposed Senior Apartment Building, City of Rosemead, California, Project No. 2920024-02, dated April 1, 1993

(b) Third Party Review of Geotechnical Report, Proposed Senior Citizens Apartment Complex, Angelus Avenue, Rosemead, California, dated February l, 1994, prepared by Paul Davis, CEG

At your request, we have prepared this response lo the preliminary review comments to our subject report (Reference a) as presented by Paul Davis in his review (Reference b). Our responses are numbered sequentially to match those of the preliminary review.

Comment 1:

"As the site is within an Alquist-Priolo (AP) Special Studies Zone, please delineate the AP Zone boundaries, and any included fault traces, with respect to the project site and explorations."

Response 1:

Figure 2, the Fault Related Features Map, included here, illustrates the location of the site with respect to the AP Zone and lhc trace of the fault as mapped within the rone by CDMG. The El Monte Quadrangle Special Studies Zone Map (Reference 2 in the original report) was used as the base map for Figure 2.

1470 soum VALLEY VISTA DRIVE, SUITE 150, DIAMOND BAR, CALIFORNIA 91765 19091860-7772 • \8001777-2286 FAX \909) 860-1089


2920024-02

Comment 2:

"Fault-related surface features as well as near-surface faulling have been reported within the immediate site vicinity (page 6). Please depict on a map of suitable scale the trend of the referenced fault(s), fault scarp, and their relation Lo the project."

Response 2:

Figure 2, illustrates the location or the probable fault as mapped by CDMG. The fault was mapped in this area, based upon the presence of the scarp-like feature discussed on Page 6 of our original report and closely coincides with the scarp location (Reference 6 of the original report). The location of the Delta and Rush Street site is also shown on Figure 2.

Comment 3:

"Basic soil descriptions presented on the Fault Trench log (Plate 1) are not in agreement with those in the report Findings, (Page 5). For example, the report findings and boring logs describe a slightly plastic clay between 4 and 8 or 9 feet below the ground surface, whereas tlie trench log, placed between the borings, clearly shows silly sand with gravel below 4.5 or 5 feet. This inconsistency raises a host of stratigraphic and structural questions with serious faulting implications. Please explain."

Response 3:

The slightly plastic sandy clay layer described in the text and in the boring logs corresponds to the Topsoil/Organic A Horizon of the trench log. The thickness of this unit is expected to be generally uniform across most of the site although some thickening near Alhambra Wash was noted. The contact with the alluvial terrace below is gradational in nature, making determination of this contact somewhat subjective. The depth lo the unit is controlled by the fill thickness above and may vary slighlly across the site. We do not expect this material to be found as deep as 9 feel below existing grades however. Borings B-1 and B-2 were drilled with a hollow-stem auger. With this drilling method, accurate depths of various soils encountered is difficult to determine due to the mixing of materials and the time delay as the cuttings arc moved to the surface. As such, the different soil depths shown on the boring logs arc only tightly controlled where drive samples have been obtained. The fault trench Jog presents a more accurate depiction of the upper subsurface conditions. We expect that the sandy clay topsoil and the gradational zone may be present as deep as 6.5 feet below existing grade. The boring logs for B" 1 and B-2 have been changed to more accurately depict these expected conditions and are included in this report.

. 2 -

LEIGHTON AND ASSOCIATES, INC


We hope this provides you with the information needed at this lime. Should you have any questions or eommenls, please call at your convenience.

Respectfully suhmitted,


PB/DCS/rsh

~r;~-David C. Smith, RCE 46222 Project Engineer

Attachments: Figure 1 " Fault Related Features Map Appendix A " Preliminary Review Comments of Paul Davis Appendix B - Revised Geotechnical Boring Logs B-1 and B-2

Distribution: (2) Addressee

(1) Paul Davis Certified Engineering Geologist 711 Main Street Huntington Beach, California 91770

- 3 -



. ' AV~. NLJL

eo ~~ -~200~0~~~400~0 SCALE FEET

FAULT RELATED FEATURES MAP

Base Map: U.S.G.S. 7 112 Minute Alquist-Priolo Special Studies Zone Map, El Monte Quadrangle.,

SENIOR CITIZEN HOUSING COMPLEX CITY OF ROSEMEAD, CALIFORNIA

Project No.

Eng./Geol.

Drafted by

Date

2920024-02

DCSJPB

!ah

2/15/94 Figure No. 1


Paul Davis, Consulting Engineering Geologist

711 Main Street, Huntington Beach, CA 92648, (714) 536-1075 RECE~VED

FEB 0 2 1994 February l, 1994

City of Rosemead 8638 E. Valley Blvd. Rosemead, Ca 91770

LEIGHTON & ASSOCiATE


Subject: Third P~rty Review of Geotechnical Report By Leighton and Associates, Inc., dated April 1, 1993 Proposed Senior Citizen's Apartment Complex Angeles Avenue, Rosemead

Dear Mr. Lyons:

Based on my preliminary additional geotechnical the third party review. addressed in the report

review of the subject geotechnical report, data-are needed in order to adequately complete

The. following three (3) items should be · for completeness and consistency ..

1. ;: As the site is within an Alquist-Priolo (AP) Special Studies Zone, please delineate the AP Zone boundaries, and any includeJ fault traces, with respect to the project site and explorations.

2. Fault-related surface features, as well as near-surface faulting, have been reported within the immediate site vicinity (page 6), Please depict on a map of suitable scale the trend of the referenced fault(s), fault scarp, and their relation to the project site.

3. Basic soil descriptions presented on the Fault Trench log (Plate 1) are not in agreement with those in the report Findings,(page 5). For example, the report Findings and boring logs describe a slightly plastic clay between 4 to 8 or 9 feet below the ground surface, whereas the trench log, placed between the borings, clearly shows silty sand with gravel below 1~ or 5 feet. This inconsistency raises a host of stratigraphic'and stru~tural questions with serious faulting implications. Please explain.

Once the requested data are received, the review can be completed. Please do not hesitate to call the undersigned if you or Leighton personnel have any questions or need clarification.

Respectfully,

£? .. /Jo -- , I~-~

Paul Davis, CEG 320

cc: Leighton and Assoc., Mr. Eldon G~th


GEOTECHNICAL BORING LOG B-1 Datc ___ ~2~-l~J~-9~3~--- Sheet ____!Qf _2_ Prajcct ~-------~~~R~o~s~•~m~ea....,d~A~n~a~rt""m~•~n~ts,__ _________ _ Project No.

Type of Rig 2920024--02

Drilling Co. 2-R Drilling, Inc CME55 Hole Diameter 8" Drive Weight 140 lb, Automatic Drop JOin. Elevation Top of Hole Ref or Datum

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19 118.0 15.2 CL 5': SANDY Cl.AY, slightly plasfic, fine grained sand1 reddish bJtJWTJ with oxidized Steins, very moist, finn

SM 10': SILTY SAND, mixed with gravel, gravel sizes to 1 inch, fine to coan:e P1'in«l, brown, moist, medium dense; interbedded with thin layer or sandy silt

38 115.8 16.3 SM 15': SILTY SANDi slightly rnical'.:eous, very fine grained, light brown with oxidizeQ stains, moist, very firm

26 SM 20': SIL'rY SAND, ve:ry fine grained, brown witti oxid.izecl stains, moist, medium dens~

82 112.2 13.0 SM 25': SILTY SAND, very fine grained, brown with oxidized stains, moist, dense

LEIGHTON & ASSOC IA TES


I Date ___ .::_2---'-1'-'1'----c:._9,,,_3 __ _ Sheet 2 of 2

Project ------------=-Ro.:o:::•:::e:.:m:..:•o::a:d...;A=pa"'r:..:tc::mo.:•o.on:..:t:!.s ---------- Project No. __ 2::.9,.;2::;0::.;0,,,2,__4'--__,0:..:2'----Drilling Co. ___ ......,. ____ _.:;_l_·R~D~rc:.llo.:cll:..::nctogL, ..,,ln::,:c:...,____________ Type of Rig _ ____:Co::M.:.:.::E...:5::..:5:........_ Hole Diameter 8" Drive Weight -------'1'-'4"'0_1:..:b:..i....:A=u.:.:to:..:m::.a::.t::.i:::.c _______ Drop .lQ_ m Elevation Top of Hole Ref or Datum I

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with o):fdi2.ed stains, moist, firm

10': SANDY SILT, non p1asti~ 1 very fine g:raini:d., brown, slightly moist, stiff; mixed with fine ~ined, brown, silty sand

15': SILIT SAND, fine to coarse grained, trace or gravel, slightly cemented, brown with oxidizc<f stains, slightly moilj;t, medium dense

9 98 120,5 2.4 SM 20': SIL'IY SAND, mixed with gravel, gni.vcl sizes to 1/2-inch, fine to

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coarSc grainc:dj brown to rcddi!!oh brown with gray and white g:ni.vi;:I, damp, dcni.c

251: SILTY SAND, mixed with gravel, gravel sizes lo 3/4~inch, fine to eoar.ioe grained, brown to reddish brown with gray and white gravel, damp, dense; Pocki=t.s. of sandy silt

LEIGHTON & ASSOCIATES


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Logged By CY E cc .... CJ .... • P. :J I: 0 ·..i:; w <t: ., .. 0 Jl- Sampled By CY Cl

30 .. 87 95.9 17.7 SM 30': SILTY SAND, fine (t'ained, brown, 11lightly moiet, dense . ' 10 I ,'. - ..

':-' I

. . ···:--. h . . . . . I

-· . ". ':. h ,.'.

-· .. h ' .

ss-·: . '. ..

SP'l' 27 M/M• 35': SILTY SAND, mix•d with sandy silt, very fint1 grained, brown, moist, "

- '•. medium derut•

''

- : h . •,'

I I

- . ·, h " . ' . . ·.·

" ... . . I •o

. ·.· ..

. ' 11 98 113.1 4.2 SM •O': SILTY SAND, mixed with s:r~vel 1 gravel eizes to 1-lneh, fins to coarae ·.:- gr&ined, brown with oxidiz:•d 1tains1 sliihtly moist, very dense . ' . . . :-. : ' ' . I

.. ':' ': ;'.

, . . . . ' - :- " ,. ..

I : .. · .. ·.·

45-· .. SP'l' 78 SM 4.6 1

: SILTY SAND 1 mixed with gravel, gravel 11ir.el!I to 3/4-ineh1 fin111 to . ·, toa.rz111 grained, brown with oxidh~.ed ;iitain•, :r;Ilghtly rnoi11t, very dcnss -· ..

. '. I '; . . '. - -· . ' ,. '• .

- .. ': . .. I

-· :_· .. · . : .

so- ,.

u gs 119.l 12.5 SM ~O'~ SILTY SAND 1 mi:>ted with gt-e.vel. 1 gr~vel 1i1-ca to 3/-i-inch, fine to

-. '' c:oarae g-rained, btown with oxidi£cd f.t:airui, alig-htly moi11t, very dense '•.

I -

- ,. I -

I 56- h Total depth ~ 51.5 feet Ground w:ater at 4. 7 feet -C~vint •t S6 feet Backfilled with native material.

-I -

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505A( 11/77) LEIGHTON & AS SOCIA TES

I

date: april 18, 1994...1993/04/01 · 711 main street, huntington beaeh, ca 92648, (714) 536-1075...

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