geotechnical investigation 1050 parker street berkeley ... · this report presents results of our...

GEOTECHNICAL INVESTIGATION1050 PARKER STREET

Berkeley, California

Prepared For:

Wareham Properties Group1120 Nye Street, Suite 400

San Rafael, California 94901

Prepared By:

Langan Treadwell Rollo555 Montgomery Street, Suite 1300

San Francisco, California 94111

Serena T. Jang, G.E. #2702Associate

Frank L. Rollo, G.E. #733Geotechnical Engineer

1 September 2016770632101

Geotechnical Investigation1050 Parker StreetBerkeley, California

1 September 2016Project No. 770632101

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TABLE OF CONTENTS

1.0 INTRODUCTION.............................................................................................................1

2.0 SCOPE OF SERVICES ....................................................................................................2

3.0 FIELD INVESTIGATION AND LABORATORY TESTING ...............................................23.1 Treadwell & Rollo, Inc. (2004) Investigation for Jubilee Village .....................33.2 Treadwell & Rollo, Inc. (2006) Investigation for 2600 Tenth Street................4

3.2.1 Soil Borings ............................................................................................43.2.2 Cone Penetration Tests..........................................................................53.2.3 Laboratory Testing.................................................................................5

4.0 SITE AND SUBSURFACE CONDITIONS .......................................................................6

5.0 REGIONAL SEISMICITY AND FAULTING .....................................................................7

6.0 GEOLOGIC HAZARDS .................................................................................................106.1 Ground Rupture ...............................................................................................106.2 Liquefaction and Liquefaction-Induced Settlement ......................................106.3 Lateral Spreading and Seismic Densification ................................................116.4 Tsunami............................................................................................................12

7.0 DISCUSSION AND CONCLUSIONS............................................................................127.1 Expansive Soil..................................................................................................127.2 Foundation and Settlement ............................................................................137.3 Construction Considerations ..........................................................................137.4 Corrosion Potential..........................................................................................14

8.0 RECOMMENDATIONS.................................................................................................158.1 Site Preparation ...............................................................................................158.2 Foundations .....................................................................................................188.3 Seismic Design.................................................................................................198.4 Floor Slabs........................................................................................................198.5 Asphalt Pavements..........................................................................................218.6 Concrete Pavement and Exterior slabs ..........................................................228.7 Utilities .............................................................................................................228.8 Site Drainage....................................................................................................238.9 Landscaping .....................................................................................................24

9.0 GEOTECHNICAL SERVICES DURING CONSTRUCTION............................................24

10.0 LIMITATIONS...............................................................................................................24



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LIST OF FIGURES

Figure 1 Site Location Map

Figure 2 Site Plan

Figure 3 Creek and Watershed Map

Figure 4 Map of Major Faults and Earthquake Epicentersin the San Francisco Bay Area

Figure 5 Modified Mercalli Intensity Scale

LIST OF APPENDICES

APPENDIX A – Borings, Laboratory Data and Cone Penetration Tests, Treadwell & Rollo, Inc.Investigation for 2600 Tenth Street



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GEOTECHNICAL INVESTIGATION1050 PARKER STREET

Berkeley, California

1.0 INTRODUCTION

This report presents results of our geotechnical investigation for the proposed development at

1050 Parker Street in Berkeley, California. A geotechnical report was previously prepared for a

different project at the site by our predecessor firm Treadwell & Rollo, Inc. (T&R). The report,

dated 17 May 2004, was for a development called Jubilee Village; the development was never

constructed.

The project site is at the southwest corner of the intersection of 10th and Parker Streets, as

shown on Figure 1. The site is bound by Parker Street, Tenth Street, San Pablo Avenue and

commercial buildings, as shown on Figure 2. The property consists of three parcels

encompassing approximately 1.57 acres and has the addresses of 1050 Parker Street, 2621

10th Street, 2627 10th Street, and 2612 San Pablo Avenue.

The building will be built on the northern portion of the site and asphalt paved parking and

landscaping will occupy the remainder of the site, as shown on Figure 2. According to the

drawings prepared by Gould Evans, the project architect, dated June 28, 2016, the proposed

development will consist of a two-story office building above at-grading parking and the building

lobby. The Lobby will consist of a concrete slab-on-grade and the parking areas will be paved.

According to Tipping Structural, the project structural engineer, column loads will be 330 kips

and 170 kips for interior and exterior columns, respectively. We understand several foundation

schemes are being considered, including a base isolation system.



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2.0 SCOPE OF SERVICES

Our geotechnical investigation was performed in general accordance with the scope of services outlined

in our proposal dated 27 May 2016. The scope consisted of reviewing data from previous geotechnical

studies and performing engineering analyses to develop conclusions and recommendations regarding:

• anticipated subsurface conditions including groundwater levels

• 2013 California Building Code (CBC) site classification, mapped values SS and S1,

modification factors Fa and Fv and SMS and SM1

• site seismicity and potential for seismic hazards including liquefaction, lateral spreading,

fault rupture

• appropriate foundation type(s) including shallow foundations and alternatives for deep

foundations, as necessary

• design parameters for the recommended foundation type(s), including vertical and

lateral capacities and associated estimated settlements

• subgrade preparation for slab-on-grade floors and exterior slabs and flatwork, including

sidewalks

• site preparation, grading, and excavation, including criteria for fill quality and compaction

• soil corrosivity

• construction considerations

3.0 FIELD INVESTIGATION AND LABORATORY TESTING

To evaluate subsurface conditions, we reviewed the results of previous investigations

performed at the site and vicinity, as discussed in this section. The studies are summarized in

the reports listed below:

• Geotechnical Investigation, Jubilee Village, 10th and Parker Streets, Berkeley, California

by Treadwell & Rollo, Inc. dated 17 May 2004

• Preliminary Geotechnical Evaluation, 2600 Tenth Street, Berkeley, California by

Treadwell & Rollo, Inc. dated 20 September 2006



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The Jubilee Village geotechnical investigation was performed at the project site but was

completed for a different developer; therefore the results of the investigation are not included

in this report; however, the field and laboratory test results were used to form the basis of our

recommendation. The geotechnical investigation of 2600 Tenth Street located west of the

project site was performed for Wareham Development and the logs of the test borings and

CPTs and laboratory test results are included in Appendix A of this report.

The results of the previous field exploration at the site and site vicinity are discussed in more

detail in the following sections.

3.1 Treadwell & Rollo, Inc. (2004) Investigation for Jubilee Village

Subsurface conditions were explored by T&R during the investigation for the previous proposed

Jubilee Village development at the project site by drilling three test borings, designated as TR-1

through TR-3, pushing three shallow borings, designated as S-1 through S-3, and performing

three cone penetration tests (CPTs), designated as C-1 through C-3. The approximate locations

of the borings and CPTs are shown on Figure 2.

TR-1 through TR-3 were drilled on 24 November 2003 using a truck-mounted drill rig equipped

with hollow-stem augers provided by Exploration Geoservices. The boring depths ranged from

30 feet to 40 feet below ground surface (bgs). In addition, T&R sampled the upper 2.5 to 4 feet

of soil at sample locations S-1 through S-3, on 11 March 2004, using the direct-push sampling

method where the soil was retrieved with plastic tubes four feet in length. T&R’s field

engineers logged the borings and obtained samples of the material encountered for visual

classification and laboratory testing. Upon completion, the borings were backfilled with grout

consisting of cement, bentonite and water, in accordance with City of Berkeley requirements.

T&R re-examined soil samples from the borings in our office to confirm field classifications and

selected representative soil samples for testing. Selected samples were tested to measure

moisture content, dry density, plasticity index, fines content, strength, consolidation

parameters, and corrosion potential.



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To supplement the borings and provide in-situ soil data, CPT C-1 through C-3 were advanced to

a depth of 40.5 feet bgs on 24 November 2003. The CPTs were performed by hydraulically

pushing a 1.4-inch-diameter, cone-tipped probe with a projected area of 10 square centimeters

into the ground.

3.2 Treadwell & Rollo, Inc. (2006) Investigation for 2600 Tenth Street

In 2006, T&R performed a geotechnical investigation for the 2600 Tenth Street site. The

subsurface conditions were explored at the site by drilling three test borings, designated as B-1

through B-3 and performing three cone penetration tests (CPTs), designated as CPT-1 through

CPT-3. The approximate locations of the borings and CPTs are shown on Figure 2.

3.2.1 Soil Borings

Three test borings, designated B-1 through B-3, were drilled using a truck-mounted, rotary-

wash drill rig provided by Pitcher Drilling. The test borings were drilled to depths of

approximately 40.5 to 60.5 feet bgs. T&R’s field engineers logged the borings and obtained

samples of the material encountered for visual classification and laboratory testing. Upon

completion, the borings were backfilled with grout consisting of cement, bentonite and water,

in accordance with City of Berkeley requirements.

The logs of the borings from the 2006 investigation are presented on Figures A-1 through A-3 in

Appendix A. The soil is classified in accordance with the chart shown on Figures A-4.

Soil samples were obtained using a Sprague and Henwood (S&H) split-barrel sampler with a

3.0-inch outside diameter and 2.5-inch-inside diameter, lined with brass tubes with an inside

diameter of 2.43 inches. The sampler type was chosen on the basis of soil type and desired

sample quality for laboratory testing. In general, the S&H sampler was used to obtain samples

in medium stiff to very stiff cohesive soil.



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The S&H sampler was driven with a 140-pound safety hammer falling about 30 inches. For the

S&H sampler, the blow counts required to drive the sampler the final 12 inches of an 18-inch

drive were corrected using a factor of 0.7 to approximate SPT N-blow counts and are shown on

the boring logs.

3.2.2 Cone Penetration Tests

On August 16, 2006, three CPTs, CPT-1 through CPT-3, were advanced by John Sarmiento and

Associates. The CPTs were advanced to depths ranging from 49 to 75 feet below the ground

surface. The CPT logs showing tip resistance, friction ratio, SPT N-value, shear strength,

internal friction angle, and soil classifications are presented on Figures A-5 through A-7. A

classification chart for CPTs is included as Figure A-8. The CPT holes were also backfilled with

cement grout, in accordance to City of Berkeley requirements

The CPTs were performed by hydraulically pushing a 1.4-inch diameter (ten square

centimeters), cone-tipped probe into the ground. The cone on the end of the probe measures

tip resistance, and the friction sleeve behind the cone tip measures frictional resistance.

Electrical strain gauges within the cone measure soil parameters continuously for the entire

depth advanced. Soil data, including tip resistance, was transferred to a computer while

conducting each test. Accumulated data was processed by computer to provide engineering

information, such as the types and approximate strength characteristics of the soil

encountered.

3.2.3 Laboratory Testing

The samples recovered from the field exploration program were examined for soil classification,

and representative samples were selected for laboratory testing.

T&R’s laboratory testing program was designed to correlate soil properties and to evaluate

engineering properties of the soil at the site. Samples were tested to measure moisture

content, dry density, percent fines, strength, and consolidation parameters. The test results

are presented on the boring logs and in Appendix A.



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4.0 SITE AND SUBSURFACE CONDITIONS

The area of the project site is approximately 1.57 acres. The Phase 1 ESA performed by

Langan Treadwell Rollo earlier this year reported that the property was previously occupied by

four warehouse buildings, a metal shed and two residential buildings at the southern portion of

the site. The former buildings were constructed prior to the 1930s. Previous uses of the site

included a sign shop, a printing facility and part of a lumber mill. Aerial photographs from 2009

and 2010 indicate the warehouse buildings had been demolished, though the concrete building

pads remains; aerial photographs from 2012 indicate the residential structures at the southern

portion of the site had been removed. Currently, an urban farm and at-grade parking occupy

the site. On the basis of our review of the creek and watershed maps prepared by Sowers

(2000), an underground culvert runs below San Pablo Avenue.

The ground surface at the site is relatively flat and has an elevation of approximately 201 feet1.

and the ground surface at the site vicinity slopes towards west-southwest.

Subsurface information from the previous investigation indicates the site is blanketed by up to

three feet of fill consisting of stiff clay, silt, sandy silt and sandy clay with gravel, and loose silty

sand. Laboratory test results indicate the fill has moderately expansion potential2 with plasticity

indices ranging from 18 to 22. The fill is underlain by stiff to very stiff clay to a depth of

approximately 11 to 12 feet below ground surface (bgs). Laboratory tests results indicate the

near surface clay has high expansion potential3 with plasticity indices ranging from 37 to 47 and

is overconsolidated4. Where tested, the undrained shear strengths of the near surface clays

range from approximately 1,000 to 3,000 pounds per square foot (psf).

1All elevations reference Mean Sea Level (MSL).

2Moderately expansive soil undergoes moderate volume changes in moisture content.

3Highly expansive soil undergoes large volume changes with changes in moisture content.

4An overconsolidated clay has experienced a pressure greater than its current load.



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The clay is generally underlain by interbedded layers of stiff to very stiff clay and silt with

variable sand content. Lenses of medium dense clayey sand with gravel and sand with clay

were encountered in boring TR-2 between 19½ and 37 feet bgs, and medium dense clayey

sand with gravel and dense silty sand with gravel were encountered in boring TR-3 between 12

and 27 feet bgs. These lenses varied from 2 to 9 feet thick.

Stabilized groundwater level were recorded during the field investigation for a groundwater

study that was prepared for the previous development (Treadwell & Rollo, 2004). The study

reported the groundwater level to be at approximately 7.6 to 9.25 feet bgs. The study

concluded that the groundwater level in the area fluctuate two to three feet seasonally.

5.0 REGIONAL SEISMICITY AND FAULTING

The major active faults in the area are the Hayward, Calaveras, and San Andreas faults. These

and other faults of the region are shown on Figure 4. For each of the active faults within

50 kilometers (km) of the site, the distance from the site and estimated Mean Characteristic

Moment Magnitude5 [2007 Working Group on California Earthquake Probabilities (WGCEP)

(2008) and Cao et al. (2003)] are summarized in Table 1.

5Moment magnitude is an energy-based scale and provides a physically meaningful measure of the size of a

faulting event. Moment magnitude is directly related to average slip and fault rupture area.



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TABLE 1

Regional Faults and Seismicity

Fault Segment

Approx.Distance from

fault (km)Directionfrom Site

MeanCharacteristic

MomentMagnitude

Total Hayward 3.7 East 7.00

Total Hayward-Rodgers Creek 3.7 East 7.33

Mount Diablo Thrust 22 East 6.70

Total Calaveras 25 East 7.03

N. San Andreas – Peninsula 25 West 7.23

N. San Andreas (1906 event) 25 West 8.05

Green Valley Connected 26 East 6.80

N. San Andreas - North Coast 26 West 7.51

Rodgers Creek 28 Northwest 7.07

San Gregorio Connected 31 West 7.50

West Napa 34 North 6.70

Greenville Connected 40 East 7.00

Great Valley 5, Pittsburg Kirby Hills 43 East 6.70

Monte Vista-Shannon 47 South 6.50

Point Reyes 49 West 6.90

Figure 4 also shows the earthquake epicenters for events with magnitude greater than 5.0 from

January 1800 through December 2000. Since 1800, four major earthquakes have been

recorded on the San Andreas Fault. In 1836 an earthquake with an estimated maximum

intensity of VII on the Modified Mercalli (MM) scale (Figure 5) occurred east of Monterey Bay

on the San Andreas fault (Toppozada and Borchardt 1998). The estimated Moment magnitude,

Mw, for this earthquake is about 6.25. In 1838, an earthquake occurred with an estimated

intensity of about VIII-IX (MM), corresponding to an Mw of about 7.5. The San Francisco

Earthquake of 1906 caused the most significant damage in the history of the Bay Area in terms

of loss of lives and property damage. This earthquake created a surface rupture along the

San Andreas fault from Shelter Cove to San Juan Bautista, approximately 470 kilometers in

length. It had a maximum intensity of XI (MM), a Mw of about 7.9, and was felt 560 kilometers

away in Oregon, Nevada, and Los Angeles. The most recent earthquake to affect the Bay Area

was the Loma Prieta Earthquake of 17 October 1989, in the Santa Cruz Mountains with a Mw of

6.9, approximately 98 km away from the site.



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In 1868 an earthquake with an estimated maximum intensity of X on the MM scale occurred on

the southern segment (between San Leandro and Fremont) of the Hayward fault. The

estimated Mw for the earthquake is 7.0. In 1861, an earthquake of unknown magnitude

(probably a Mw of about 6.5) was reported on the Calaveras Fault. The most recent significant

earthquake on this fault was the 1984 Morgan Hill earthquake (Mw = 6.2).

The most recent earthquake to affect the greater San Francisco Bay Area occurred on

24 August 2014 and was located on the West Napa fault, approximately 53 kilometers

northeast of the site, with a MW of 6.0.

The WGCEP (2008) at the U.S. Geologic Survey (USGS) predicts a 63 percent chance of a

magnitude 6.7 or greater earthquake occurring in the San Francisco Bay Area in 30 years. More

specific estimates of the probabilities for different faults in the Bay Area are presented in

Table 2.

TABLE 2

WGCEP (2008) Estimates of 30-Year Probabilityof a Magnitude 6.7 or Greater Earthquake

FaultProbability(percent)

Hayward-Rodgers Creek 31

N. San Andreas 21

Calaveras 7

San Gregorio 6

Concord-Green Valley 3



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6.0 GEOLOGIC HAZARDS

During a major earthquake, strong ground shaking is expected to occur at the project site.

Strong shaking during an earthquake can result in ground failure such as those associated with

soil liquefaction6, lateral spreading7, and seismic densification8. We evaluated each of these

conditions. The results of our evaluation are discussed in this section.

6.1 Ground Rupture

Historically, ground surface ruptures closely follow the trace of geologically young faults. The

site is not within an Earthquake Fault Zone, as defined by the Alquist-Priolo Earthquake Fault

Zoning Act and no known active or potentially active faults exist on the site. Therefore, we

conclude the risk of fault offset at the site from a known fault is low. In a seismically active

area, the remote possibility exists for future faulting in areas where no faults previously

existed; however, we conclude the risk of surface faulting and consequent secondary ground

failure is low.

6.2 Liquefaction and Liquefaction-Induced Settlement

When a saturated, cohesionless soil liquefies during a major earthquake, it experiences a

temporary loss of shear strength as a result of a transient rise in excess pore water pressure

generated by strong ground motion. Flow failure, lateral spreading, differential settlement, loss

of bearing, ground fissures, and sand boils are evidence of excess pore pressure generation

and liquefaction.

6Liquefaction is a transformation of soil from a solid to a liquefied state during which saturated soil temporarily

loses strength resulting from the buildup of excess pore water pressure, especially during earthquake-inducedcyclic loading. Soil susceptible to liquefaction includes loose to medium dense sand and gravel, low-plasticitysilt, and some low-plasticity clay deposits.

7Lateral spreading is a phenomenon in which surficial soil displaces along a shear zone that has formed within an

underlying liquefied layer. Upon reaching mobilization, the surficial blocks are transported downslope or in thedirection of a free face by earthquake and gravitational forces.

8Seismic densification is a phenomenon in which non-saturated, cohesionless soil is densified by earthquake

vibrations, causing differential settlement.



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The site is in an area designated by the California Geologic Survey (formerly California Division

of Mines and Geology) as a zone of potential liquefaction (California Geologic Survey, 2003).

Our liquefaction analyses were performed in accordance with the methodology presented in

the publication titled Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER

and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils (Youd, T.L.,

and Idriss, I.M., 2001). The level of ground shaking used in our liquefaction evaluation was

based on the Risk-Target Maximum Considered Earthquake (MCER) mapped values. A peak

ground acceleration (geometric mean) (PGAM) of 0.76g was used in our analyses. This PGA is

based on the 2013 California Building Code (CBC) mapped values, using site class D. We

assumed an earthquake magnitude of 7.3 in our analyses and the groundwater levels reported

in the 2004 studies – 7½ to 9½ feet bgs.

On the basis of the results of our analyses, the medium dense silty and clayey sands lenses

encountered between 19 to 25 feet and 31½ to 37 feet bgs could be susceptible to pore

pressure buildup, liquefaction, and strength loss during a major earthquake. These potentially-

liquefiable lenses are about ¾ to 5½ inches thick and were encountered at depths of

approximately 15 to 27½ feet below the proposed bottom foundation level; however, they

appear to be discontinuous. We estimate these layers could settle about one inch during and

immediately after a major earthquake. Because the potentially liquefiable layers are

discontinuous, we estimate that up to ¾ inch of differential settlement at the ground surface

may occur during an earthquake.

6.3 Lateral Spreading and Seismic Densification

Because of the gradient of the site and the discontinuous nature of the sand lenses, we

conclude the likelihood of lateral spreading is low; there is no historical evidence of lateral

spreading at the site or vicinity. Also, because the soil encountered above the groundwater

table is cohesive, the potential for seismic densification during an earthquake is low.



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6.4 Tsunami

According to recent published maps (California Emergency Agency, 2009), the project site is

not within the tsunami inundation zone; therefore, we conclude the potential risk by inundation

from tsunami to be low.

7.0 DISCUSSION AND CONCLUSIONS

On the basis of the results of our earlier investigation and our experience with similar sites in

the immediate vicinity, we conclude the project is feasible from a geotechnical standpoint. The

main geotechnical issues are foundation support, geologic hazards, and the presence of

expansive and undocumented fill.

7.1 Expansive Soil

Expansive surface soil is subject to volume changes during seasonal fluctuations in moisture

content. These volume changes can cause cracking of foundations and floor slabs. Therefore,

foundations and slabs should be designed and constructed to resist the effects of the

expansive soil. These effects can be mitigated by moisture conditioning the expansive soil and

providing select, non-expansive fill within the zone of seasonal moisture change beneath

interior and exterior slabs and supporting foundations.

To mitigate the effects of the expansive soil, we recommend spread footings be bottomed at

least 24 inches below lowest adjacent soil subgrade. Current plans indicate that the ground

floor level of the building will be asphalt paved, except for the building lobby which will be

covered by a concrete slab to reduce the potential for damage. The slab-on-grade should be

underlain by 18 inches of select fill. Alternatively, the subgrade may be lime treated to a depth

of 18-inches or the slab may be designed as a structural slab that spans between column lines.

During final design, a cost study analysis can be performed to evaluate the placement of select

fill versus lime treatment alternatives.

Previous experience with similar soil types indicates exterior concrete slabs-on-grade should

perform satisfactorily if they are supported on a layer of select fill at least 12 inches thick.



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7.2 Foundation and Settlement

The results of consolidation testing indicate the on-site clay is overconsolidated. Settlement

will be dependent on the amount of new fill placed and the building loads. Plans indicate the

site will be graded with up to two feet of new fill and the proposed building will be constructed

at-grade. Where new fill is placed, we anticipate approximately ¼-inch and ½-inch of

consolidation settlement for one and two feet of new fill, respectively.

The proposed buildings can be supported on shallow foundations (spread footings or mat

foundations) that are founded on the native soil and near the bottom of the zone of severe

moisture change. Localized soft soil, if encountered under footing locations, should be

excavated and replaced with lean concrete.

Design recommendations for building footings are presented in Section 8.2. Footings designed

in accordance with these recommendations should not settle more than two inches; differential

settlement between adjacent footings, typically 30 feet apart, should not exceed one inch.

As discussed previously, we estimate that up to one inch of liquefaction-induced settlements

may occur; differential settlement between columns may be on the order of ¾ inch during a

major earthquake. These settlements are in addition to the predicted consolidation static

settlement. The structural engineer should evaluate the impact of liquefaction-induced

settlement to structures supported on shallow foundations. If the total and differential

settlements are not tolerable than a stiffer foundation system such as an interconnected grid

system or mat should be used.

7.3 Construction Considerations

The soil at the site consists predominantly of clay that can be excavated with conventional

equipment such as a backhoe and/or a front-end loader. Heavier equipment including jack

hammers and hoe rams may be required to demolish and remove foundations, slabs and walls

from the former underground tanks and buildings that once occupied the site. Debris, concrete



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rubble, foundations and walls from former buildings should be removed from the site. All

excavations that extend below the final soil subgrade should be filled with approved compacted

on-site soil.

As previously discussed, the site is underlain by moderately to highly expansive near-surface

soil. If the soil subgrade is exposed and allowed to dry during excavation for the foundations

and subgrade preparation and is not properly moisture-conditioned prior to placement of

concrete, heave may occur as soil moisture levels increase after construction. Therefore, it is

essential to maintain the soil in a moist state during foundation and slab construction. Typically,

it is necessary to spray the exposed bottom and sides of foundation excavations on a daily

basis to prevent drying.

If earthwork is performed in wet weather conditions, it may be difficult to compact the soil; it

may need to be aerated. Light grading equipment may be needed to avoid damaging the

subgrade.

7.4 Corrosion Potential

Corrosivity tests were performed on samples collected during the previous investigation for the

site.

During the previous investigation at the site, select samples were sent to Environmental

Technical Services (ETS) to evaluate corrosion potential to buried metals and concrete. The

results of the tests are summarized in Table 3.

TABLE 3

Summary of Corrosivity Test Results

TestBoring

Sample Depth(feet) pH

Sulfate(ppm)

Resistivity(ohms-cm)

Redox(mV)

Chloride(ppm)

TR-1 1 6.08 216 1,320 533 42

TR-3 3.5 6.17 99 1,690 544 36



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The results of resistivity measurements indicate the soil samples tested are classified as

“slightly corrosive” to buried iron, steel, cast iron, ductile iron, galvanized steel and dielectric

coated steel or iron. The chemical analysis indicates reinforced concrete and cement mortar

coated steel, should not be affected by the corrosivity of the soil. To protect reinforcing steel

from corrosion, adequate coverage should be provided as required by the building code.

For more detailed recommendations regarding the corrosion protection of buried metals and

concrete, a licensed corrosion consultant should be retained.

8.0 RECOMMENDATIONS

Our recommendations regarding earthwork, foundation support, floor slabs, seismic design and

other geotechnical aspects of this project are presented in the remainder of this report.

8.1 Site Preparation

Demolition in areas to be developed should include removal of existing pavement, concrete

slabs and underground obstructions, including foundations of existing structures. Any

vegetation and organic topsoil should be stripped in areas to receive new site improvements.

Stripped organic soil can be stockpiled for later use in landscaped areas, if approved by the

owner and architect; organic topsoil should not be used as compacted fill.

Demolished asphalt and concrete at the site may be crushed to provide recycled construction

materials, including sand, free-draining crushed rock, and Class 2 aggregate base (AB) provided

it is acceptable from an environmental standpoint. Where crushed rock will be used beneath

vapor retarders and in other applications where free-draining materials are required, it should

have no greater than six percent of material passing the 3/8-inch sieve and meet the other

requirements presented in Section 8.4. Where recycled Class 2 AB will be used beneath

pavements, it should meet requirements of the Caltrans Standard Specifications. Recycled

Class 2 AB that does not meet the Caltrans specifications should not be used beneath City

streets, but it is acceptable for use as select fill within building pads and beneath concrete

flatwork, provided it meets the requirements for select fill as presented later in this section.



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Existing underground utilities beneath areas to receive new improvements should be removed

or abandoned in-place by filling them with grout. The procedure for in-place abandonment of

utilities should be evaluated on a case-by-case basis, and will depend on location of utilities

relative to new improvements. However, in general, existing utilities within four feet of final

grades should be removed, and the resulting excavation should be properly backfilled in

accordance with the recommendations presented in this section.

Prior to placing fill, the subgrade exposed after stripping and site clearing, as well as other

portions of the site that will receive new fill or site improvements, should be scarified to a

depth of at least eight inches, moisture-conditioned to at least three percent above the

optimum moisture content, and compacted to at least 88 to 92 percent relative compaction,

where the exposed material consists of moderately to highly expansive soil. Where lean clay or

sandy soil are encountered during grading, the scarified surface should be moisture-conditioned

to above the optimum moisture content and compacted to at least 90 percent relative

compaction. An exception to this general procedure is within any proposed vehicle pavement

areas, where the upper six inches of the pavement subgrade should be compacted to at least

95 percent relative compaction regardless of expansion potential.

Heavy construction equipment should not be allowed directly on the final subgrade. The clay

exposed at the foundation level may be susceptible to disturbance under construction

equipment loads. If the subgrade is disturbed during the rainy season, it may be necessary to

place a minimum 12-inch working pad consisting of crushed rock on top of the subgrade or lime

treating the upper 12 inches of the subgrade to winterize it. Any select fill placed during

grading should meet the following criteria:

• be free of organic matter

• contain no rocks or lumps larger than three inches in greatest dimension

• have a low expansion potential (defined by a liquid limit of less than 40 and plasticity

index lower than 12 but greater than 8)



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• have a low corrosion potential

• be approved by the geotechnical engineer.

All fill placed beneath improvements should meet the criteria for select fill previously discussed

in this section. All select fill should be moisture-conditioned to above optimum moisture

content, placed in horizontal lifts not exceeding eight inches in loose thickness, and be

compacted to at least 90 percent relative compaction, except for fill that is placed within the

proposed pavement areas. In these situations, the upper six inches of the soil subgrade, all

select fill and aggregate baserock materials should be compacted to at least 95 percent relative

compaction. Samples of on-site and proposed import fill materials should be submitted to the

geotechnical engineer for approval at least three business days prior to use at the site.

We recommend that at least 12 inches of select fill be placed above native soil in areas that will

have concrete flatwork, and 18 inches beneath building slabs-on-grade. Materials for capillary

break (sand and gravel) should not count as part of the select fill. The select fill should extend

at least five feet beyond building footprints. Select material should meet the criteria presented

earlier in this section.

Alternatively, instead of placing select fill, the upper 18 inches of the existing surface soil in

building pads may be lime treated to reduce the expansion potential and help winterize the site.

We recommend that at least 5 percent lime by weight of the soil be used to treat the upper

18 inches of native soil for at-grade structures. The lime treatment should extend at least

five feet beyond building footprints where hardscape areas are planned; however, landscape

areas should not be lime treated because the lime treated soil may make it difficult for the

plants to survive. In landscape areas adjacent to building footprints and exterior slabs, select fill

should be placed. The lime treatment contractor should evaluate the type and amount of lime

to reduce the plasticity index of the soil to meet the select fill criteria.



Page 18

8.2 Foundations

The building should be supported on shallow, spread footings bearing on firm, native soil or

engineered fill. The bottom of the footings should be embedded at least 24 inches below the

lowest adjacent soil subgrade and should be at least 18 inches wide for continuous footings

and 24 inches for isolated spread footings. Footings adjacent to utility trenches should bear

below an imaginary 1.5:1 (horizontal to vertical) plane projected upward from the bottom edge

of the utility trench (or adjacent footings).

For the recommended minimum embedment, the footings bearing on firm native soil or

engineered fill may be designed for an allowable bearing pressure of 3,500 psf for dead plus

live loads, with a one-third increase for total loads, including wind and/or seismic loads.

Lateral loads can be resisted by a combination of passive pressure acting on the vertical faces

of the new and existing footings and friction along the base of the footings. Passive resistance

may be calculated using an uniform pressure of 1,200 psf. The upper one foot of soil should be

ignored unless it is confined by slabs. Frictional resistance should be computed using a

coefficient of base friction of 0.30 (assumes no waterproofing membrane is installed beneath

the foundation). The passive resistance and base friction coefficient values include a factor of

safety of at least 1.5.

Weak soil or non-engineered fill encountered in the bottom of footing excavations should be

excavated and replaced with lean concrete. The bottoms and sides of the footing excavations

should be wetted following excavation and maintained in a moist condition until concrete is

placed.

We should check footing excavations prior to placement of reinforcing steel. Footing

excavations should be free of standing water, debris, and disturbed materials prior to placing

concrete.



Page 19

8.3 Seismic Design

For seismic design in accordance with the provisions of 2013 CBC/ASCE 7-10, we recommend

the following:

• Risk Targeted Maximum Considered Earthquake (MCER) SS and S1 of 1.970g and

0.799g, respectively.

• Site Class D

• Site Coefficients FA and FV of 1.0 and 1.5

• Maximum Considered Earthquake (MCE) spectral response acceleration parameters at

short periods, SMS, and at one-second period, SM1, of 1.970g and 1.199g, respectively.

• Design Earthquake (DE) spectral response acceleration parameters at short period, SDS,

and at one-second period, SD1, of 1.313g and 0.799g, respectively.

8.4 Floor Slabs

Where the ground floor slab will be a concrete slab-on-grade, the concrete slab should be

underlain by at least 18 inches of properly compacted select fill (measured from the bottom of

the capillary break layer of the moisture barrier), as recommended in Section 8.1. Where slab-

on-grade floors are to be cast, the soil subgrade should be scarified to a depth of six inches,

moisture conditioned to above optimum moisture content, and rolled to provide a firm, non-

yielding surface compacted to at least 95 percent relative compaction. If the subgrade is

disturbed during excavation for footings and utilities, it should be re-rolled. Loose, disturbed

materials should be excavated, removed, and replaced with engineered fill during final subgrade

preparation.

Moisture is likely to condense on the underside of the slabs, even though they will be above

the design groundwater table. Consequently, a moisture barrier should be installed beneath

the slabs if movement of water vapor through the slabs would be detrimental to its intended



Page 20

use. A moisture barrier is generally not required beneath parking garage slabs, except for areas

beneath mechanical, electrical, and storage rooms. A typical moisture barrier consists of a

capillary moisture break and a water vapor retarder.

The capillary moisture break should consist of at least four inches of clean, free-draining gravel

or crushed rock. The vapor retarder should meet the requirements for Class C vapor retarders

stated in ASTM E1745-97. The vapor retarder should be placed in accordance with the

requirements of ASTM E1643-98. These requirements include overlapping seams by

six inches, taping seams, and sealing penetrations in the vapor retarder. The particle size of the

gravel/crushed rock should meet the gradation requirements presented in Table 4.

TABLE 4

Gradation Requirements for Capillary Moisture Break

Sieve Size Percentage Passing Sieve

Gravel or Crushed Rock

1 inch 90 – 100

3/4 inch 30 – 100

1/2 inch 5 – 25

3/8 inch 0 – 6

Concrete mixes with high water/cement (w/c) ratios result in excess water in the concrete,

which increases the cure time and results in excessive vapor transmission through the slab.

Therefore, concrete for the floor slab should have a low w/c ratio - less than 0.50. If approved

by the project structural engineer, the sand can be eliminated and the concrete can be placed

directly over the vapor retarder, provided the w/c ratio of the concrete does not exceed 0.45

and water is not added in the field. If necessary, workability should be increased by adding

plasticizers. In addition, the slab should be properly cured. Before the floor covering is placed,

the contractor should check that the concrete surface and the moisture emission levels (if

emission testing is required) meet the manufacturer’s requirements.



Page 21

8.5 Asphalt Pavements

Where the ground floor slab will be asphalt paved, the asphalt concrete pavement section may

be designed using the State of California flexible pavement design method. We expect the

final soil subgrade in asphalt-paved areas will generally consist of clay and sandy clay. Based

on laboratory test results of the near surface soils, we have selected an R-value of 5 for design.

If the existing subgrade elevation is raised, the fill material should have the same or higher

R-value than the native soil; additional tests should be performed on imported fill to measure its

R-value. Depending on the results of the tests, the pavement design may need to be revised.

Traffic data are not available for the proposed parking lots and roadways. For our calculations,

we assumed a Traffic Index (TI) of 5 for automobile parking areas with occasional trucks, and 6

for driveways and truck-use areas; these TIs should be confirmed by the project civil engineer.

Table 5 presents our recommendations for asphalt pavement sections.

TABLE 5

Pavement Section Design

TIAsphaltic Concrete

(inches)

Class 2 Aggregate BaseR = 78

(inches)

5 2.5 11.0

6 3.0 13.5

Pavement components should conform to the current Caltrans Standard Specifications. The

upper six inches of the soil subgrade in pavement areas should be moisture-conditioned to

above optimum and compacted to at least 95 percent relative compaction and rolled to provide

a smooth non-yielding surface. Aggregate base should be compacted to at least 95 percent

relative compaction.



Page 22

8.6 Concrete Pavement and Exterior slabs

Differential ground movement created by the shrink/swell of expansive soil and settlement will

tend to distort and crack the pavements and exterior improvements such as courtyards and

sidewalks. Periodic repairs and replacement of exterior improvements should be expected

during the life of the project. Mastic joints or other positive separations should be provided to

permit any differential movements between exterior slabs and the buildings.

To reduce the potential for cracking related to expansive soil, we recommend exterior concrete

flatwork be underlain by at least 12-inches of select fill, of which the upper four inches should

consist of aggregate base compacted to at least 90 percent relative compaction for non-

vehicular areas. The subgrade should be compacted to at least 90 percent relative compaction,

and should provide a smooth, non-yielding surface for support of the concrete slabs.

Where rigid pavement is required for loading and service areas, we recommend a minimum of

six inches of concrete for medium traffic and a minimum of eight inches of concrete for heavy

traffic. The upper six inches of subgrade should be compacted to at least 95 percent relative

compaction and should provide a smooth, non-yielding surface. The concrete should be

underlain by at least 6 inches of Class 2 Aggregate base. Aggregate base material should

conform to the current State of California Department of Transportation (Caltrans) Standard

Specifications.

8.7 Utilities

Corrosion protection measures for the project should be implemented, if appropriate. A

corrosion engineer should be retained when detailed corrosion protection recommendations are

needed.

Utility trenches should be excavated a minimum of four inches below the bottom of pipes or

conduits and have clearances of at least four inches on each side. To prevent cave-ins, trench

excavations should be shored and braced, in accordance with all safety regulations.



Page 23

Backfill for utility trenches should be compacted according to the recommendations presented

for the general site fill (Section 8.1). Jetting of trench backfill is not permitted. To provide

uniform support, pipes or conduits should be bedded on a minimum of four inches of sand or

fine gravel. After pipes and conduits are tested, inspected (if required), and approved, they

should be covered to a depth of six inches with sand or fine gravel, which should then be

mechanically tamped. Backfill should be placed in lifts of eight inches or less, moisture-

conditioned, and compacted to at least 90 percent relative compaction. If sand or gravel with

less than 10 percent fines (particles passing the No. 200 sieve) is used, it should be compacted

to 95 percent relative compaction.

Special care should be taken in controlling utility backfilling in pavement areas. Poor

compaction may cause excessive settlements, resulting in damage to exterior improvements.

Where utility trenches backfilled with sand or gravel enter the building pads, an impermeable

plug consisting of low-expansion potential clay or lean concrete, at least five feet in length,

should be installed at the building line. Furthermore, where sand- or gravel-backfilled trenches

cross planter areas and pass below asphalt or concrete pavements, a similar plug should be

placed at the edge of the pavement. The purpose of these plugs is to reduce the potential for

water to become trapped in trenches beneath the building or pavements. Trapped water can

cause heaving of soil beneath slabs and softening of subgrade beneath pavements.

8.8 Site Drainage

Drainage control design should include provisions for positive surface gradients so that surface

runoff is not permitted to pond, particularly adjacent to structures, or on roadways or

pavements. To reduce the potential for water ponding adjacent to the buildings, we

recommend the ground surface within a horizontal distance of five feet from the buildings be

designed to slope down and away from the buildings with a surface gradient of at least

two percent in unpaved areas and one percent in paved areas. In addition, roof downspouts

should be discharged into controlled drainage facilities to keep the water away from the

foundations.



Page 24

8.9 Landscaping

The use of water-intensive landscaping around the perimeter of the buildings should be avoided

to reduce the amount of water introduced to the subgrade. Irrigation of landscaping around the

building should be limited to drip or bubbler-type systems. Trees with large roots or have high

water demand should also be avoided since they can dry out the soil beneath foundations and

cause settlement. The purpose of these recommendations is to avoid large differential

moisture changes adjacent to the foundations, which have been known to cause significant

differential movement over short horizontal distances in expansive soil, resulting in cracking of

slabs and architectural damage.

To reduce the potential for irrigation water entering the pavement section, vertical curbs

adjacent to landscaped areas should extend through any aggregate base and at least six inches

into the underlying soil. In heavily watered areas, such as lawns, it may also be necessary to

install a subdrain behind the curb to intercept excess irrigation water.

9.0 GEOTECHNICAL SERVICES DURING CONSTRUCTION

We should review the final project plans and specifications to check that they are in general

conformance with the intent of our recommendations. During construction, our field engineer

should provide on-site observation and testing during site preparation, grading, placement and

compaction of fill, and foundation excavation. These observations will allow us to compare

actual with anticipated soil conditions and to check that the contractor's work conforms to the

geotechnical aspects of the plans and specifications.

10.0 LIMITATIONS

The conclusions and recommendations presented in this report result from engineering studies

based on our interpretation of the subsurface conditions encountered in the borings. Actual

subsurface conditions may vary. If any variations or undesirable conditions are encountered

during construction, or if the proposed construction will differ from that described in this report,

Langan Treadwell Rollo should be notified to provide supplemental recommendations, as

necessary.

REFERENCES

California Division of Mines and Geology (1996). “Probabilistic Seismic Hazard Assessment forthe State Of California.” DMG Open-File Report 96-08.

Cao, T., Bryant, W. A., Rowshandel, B., Branum D. and Wills, C. J. (2003). “The Revised 2002California Probabilistic Seismic Hazard Maps.

California Building Code (2013).

California Emergency Management Agency (2009). “Tsunami Inundation Map for EmergencyPlanning, Oakland West Quadrangle, State of California, County of Alameda”.

Langan Treadwell Rollo (2016). “Phase 1 Environmental Site Assessment, 1050 Parker Street,Berkeley, California” 20 July.

Sowers, J.M (2000). “Creek & Watershed Map of Oakland and Berkeley.” Oakland Museum ofCalifornia, Oakland, CA.

Toppozada, T. R. and Borchardt G. (1998). “Re-Evaluation of the 1836 “Hayward Fault” and the1838 San Andreas Fault earthquakes.” Bulletin of Seismological Society of America, 88(1), 140159.

Tokimatsu, K. and Seed, H.B. (1984). “Simplified procedures for the evaluation of settlementsin sands due to earthquake shaking.” Report no. UCB/EERC-84/16.

Tokimatsu, K. and Seed, H.B. (1987). “Evaluation of settlements in sand due to earthquakeshaking.” Journal of Geotechnical Engineering, Vol. 113 (8): 861-878.

Townley, S. D. and Allen, M. W. (1939). “Descriptive Catalog of Earthquakes of the PacificCoast of the United States 1769 to 1928.” Bulletin of the Seismological Society of America,29(1).

Treadwell & Rollo, Inc. (2006). “Preliminary Geotechnical Evaluation, 2600 Tenth Street,Berkeley, California.” 20 September

Treadwell & Rollo, Inc. (2004). “Additional Groundwater Investigation, 10th and Parker Streets,Berkeley, California.” 27 April

Treadwell & Rollo, Inc. (2004) “Geotechnical Investigation, Jubilee Village, 10th andParker Streets, Berkeley, California.” 17 May.

Working Group on California Earthquake Probabilities (WGCEP) (2007). “The Uniform CaliforniaEarthquake Rupture Forecast, Version 2.” Open File Report 2007-1437.

Youd and Idriss (2001). “Liquefaction Resistance of Soils: Summary Report from the 1996NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils.”Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, April 2001.

FIGURES

NOTES:

World street basem ap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Sources: Esri, DeLorm e, NAV TEQ, USGS, Interm ap, iPC, NRCAN. .

0 2,0001,000

Feet

1050 PARKER STREETBerkeley, California

Date 07/19/16

SITE LOCATION MAP

Project No. 770632101 Figure 1Path: \\langan.com \data\SJO\data1\770632101\ArcGIS\ArcMap_Docum ents\Site Location Map.m xd User: agek as

SITE

PARKER STREET

TENTH

STREET

2600TENTH STREET

CARLETON STREET

B-1SA

N PA

BLO

AVEN

UE

NIN

TH STR

EET

B-2

1050PARKERSTREET

B-3

CPT-2

CPT-3

CPT-1

C-1

C-2

S-3

S-1

C-3

S-2

TR-3

TR-2

TR-1

Date Project No. Figure

SITE PLAN

Berkeley, California1050 PARKER STREET

277063210108/22/16

Approximate location of boring byTreadwell & Rollo, Inc., 2003

Approximate location of cone penetrationtest by Treadwell & Rollo, Inc., 2003

Approximate location of surface soilsampling by Treadwell & Rollo, Inc., 2003

Approximate location of boring byTreadwell & Rollo, Inc., August 2006

Approximate location of cone penetrationtest by Treadwell & Rollo, Inc., August2006

Footprint of proposed building

Building slab on ground floor

Site boundary

EXPLANATION

Approximate scale

0 60 Feet

Reference: Base map from a drawing titled "Ground Floor Plan," Sheet A2.0, by Gouldevans, dated 06/28/16 and "Scheme 2 Site Plan," by gouldevans.

B-1

C-1

TR-1

CPT-1

S-1

Project No. FigureDate

CREEK AND WATERSHED MAP

SITE

Reference: Creek & Watershed Map of Oakland and Berkeley, by Sowers, dated 2000.

EXPLANATION

77063210102/27/14 3


Creeks

Former buried or drained, and Bayshoreline, circa 1850

Underground culverts and stromdrains

Engineered channels

Willow groves circa 1850

Beach, circa 1850

Tidal marsh, circa 1950

Bay

Present watersheds

0 4,000 Feet

Approximate scale

2,000

PA C I F I CPA C I F I C O C E A N O C E A N

Alameda

Amador

Calaveras

Yolo

ContraCosta

Fresno

Merced

Monterey

Napa

Sacramento

SanBenito

SanJoaquin

SanMateo Santa

Clara

SantaCruz

SolanoSonoma

Stanislaus

Marin

Grea

tVa

lley 9

GreatValley 8

Great Valley 4b

Quien SabeMount Diablo Thrust

West Napa Great Valley 5Point Reyes

Rodgers Creek

Great Valley 10

Monte Vista-Shannon

Greenville Connected

Green Valley

Zayante-Vergeles

San Andreas

Rinconada

Ortigalita

Monterey Bay-Tularcitos

SAF - creeping segment (jl0.sa-creep, modified)

Total Calaveras

San Gregorio ConnectedHayward

q

Date 7/19/2016

MAP OF MAJOR FAULTS ANDEARTHQUAKE EPICENTERS IN

THE SAN FRANCISCO BAY AREAProject No. 770632101 Figure 4

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0 10 205

Miles

Earthquake EpicenterMagnitude 5 to 5.9Magnitude 6 to 6.9Magnitude 7 to 7.4Magnitude 7.5 to 8FaultCounty Boundary

Notes: 1. Quaternary fault data displayed are based on a generalized version of U.S Geological

Survey (USGS) Quaternary Fault and fold database, 2010. For cartographic purposes only.

2. The Earthquake Epicenter (Magnitude) data is provided by the USGS and is current through 08/26/2014.

3. Basemap hillshade and County boundaries provided by USGS and California Department of Transportation.

4. Map displayed in California State Coordinate System, California (Teale) Albers, North American Datum of 1983 (NAD83), Meters.

SITE


Project No. FigureDate

I Not felt by people, except under especially favorable circumstances. However, dizziness or nausea may be experienced.Sometimes birds and animals are uneasy or disturbed. Trees, structures, liquids, bodies of water may sway gently, and doors may swing very slowly.

II Felt indoors by a few people, especially on upper floors of multi-story buildings, and by sensitive or nervous persons.As in Grade I, birds and animals are disturbed, and trees, structures, liquids and bodies of water may sway. Hanging objects swing, especially if they are delicately suspended.

III Felt indoors by several people, usually as a rapid vibration that may not be recognized as an earthquake at first. Vibration is similar to that of a light, or lightly loaded trucks, or heavy trucks some distance away. Duration may be estimated in some cases.

Movements may be appreciable on upper levels of tall structures. Standing motor cars may rock slightly. IV Felt indoors by many, outdoors by a few. Awakens a few individuals, particularly light sleepers, but frightens no one except those

apprehensive from previous experience. Vibration like that due to passing of heavy, or heavily loaded trucks. Sensation like a heavy body striking building, or the falling of heavy objects inside.

Dishes, windows and doors rattle; glassware and crockery clink and clash. Walls and house frames creak, especially if intensity is in the upper range of this grade. Hanging objects often swing. Liquids in open vessels are disturbed slightly. Stationary automobiles rock noticeably.

V Felt indoors by practically everyone, outdoors by most people. Direction can often be estimated by those outdoors. Awakens many, or most sleepers. Frightens a few people, with slight excitement; some persons run outdoors.

Buildings tremble throughout. Dishes and glassware break to some extent. Windows crack in some cases, but not generally. Vases and small or unstable objects overturn in many instances, and a few fall. Hanging objects and doors swing generally or considerably. Pictures knock against walls, or swing out of place. Doors and shutters open or close abruptly. Pendulum clocks stop, or run fast or slow. Small objects move, and furnishings may shift to a slight extent. Small amounts of liquids spill from well-filled open containers. Trees and bushes shake slightly.

VI Felt by everyone, indoors and outdoors. Awakens all sleepers. Frightens many people; general excitement, and some persons run outdoors.Persons move unsteadily. Trees and bushes shake slightly to moderately. Liquids are set in strong motion. Small bells in churches and schools ring. Poorly built buildings may be damaged. Plaster falls in small amounts. Other plaster cracks somewhat. Many dishes and glasses, and a few windows break. Knickknacks, books and pictures fall. Furniture overturns in many instances. Heavy furnishings move.

VII Frightens everyone. General alarm, and everyone runs outdoors.People find it difficult to stand. Persons driving cars notice shaking. Trees and bushes shake moderately to strongly. Waves form on ponds, lakes and streams. Water is muddied. Gravel or sand stream banks cave in. Large church bells ring. Suspended objects quiver. Damage is negligible in buildings of good design and construction; slight to moderate in well-built ordinary buildings; considerable in poorly built or badly designed buildings, adobe houses, old walls (especially where laid up without mortar), spires, etc. Plaster and some stucco fall. Many windows and some furniture break. Loosened brickwork and tiles shake down. Weak chimneys break at the roofline. Cornices fall from towers and high buildings. Bricks and stones are dislodged. Heavy furniture overturns. Concrete irrigation ditches are considerably damaged.

VIII General fright, and alarm approaches panic.Persons driving cars are disturbed. Trees shake strongly, and branches and trunks break off (especially palm trees). Sand and mud erupts in small amounts. Flow of springs and wells is temporarily and sometimes permanently changed. Dry wells renew flow. Temperatures of spring and well waters varies. Damage slight in brick structures built especially to withstand earthquakes; considerable in ordinary substantial buildings, with some partial collapse; heavy in some wooden houses, with some tumbling down. Panel walls break away in frame structures. Decayed pilings break off. Walls fall. Solid stone walls crack and break seriously. Wet grounds and steep slopes crack to some extent. Chimneys, columns, monuments and factory stacks and towers twist and fall. Very heavy furniture moves conspicuously or overturns.

IX Panic is general.Ground cracks conspicuously. Damage is considerable in masonry structures built especially to withstand earthquakes; great in other masonry buildings - some collapse in large part. Some wood frame houses built especially to withstand earthquakes are thrown out of plumb, others are shifted wholly off foundations. Reservoirs are seriously damaged and underground pipes sometimes break.

X Panic is general.Ground, especially when loose and wet, cracks up to widths of several inches; fissures up to a yard in width run parallel to canal and stream banks. Landsliding is considerable from river banks and steep coasts. Sand and mud shifts horizontally on beaches and flat land. Water level changes in wells. Water is thrown on banks of canals, lakes, rivers, etc. Dams, dikes, embankments are seriously damaged. Well-built wooden structures and bridges are severely damaged, and some collapse. Dangerous cracks develop in excellent brick walls. Most masonry and frame structures, and their foundations are destroyed. Railroad rails bend slightly. Pipe lines buried in earth tear apart or are crushed endwise. Open cracks and broad wavy folds open in cement pavements and asphalt road surfaces.

XI Panic is general.Disturbances in ground are many and widespread, varying with the ground material. Broad fissures, earth slumps, and land slips develop in soft, wet ground. Water charged with sand and mud is ejected in large amounts. Sea waves of significant magnitude may develop. Damage is severe to wood frame structures, especially near shock centers, great to dams, dikes and embankments, even at long distances. Few if any masonry structures remain standing. Supporting piers or pillars of large, well-built bridges are wrecked. Wooden bridges that "give" are less affected. Railroad rails bend greatly and some thrust endwise. Pipe lines buried in earth are put completely out of service.

XII Panic is general.Damage is total, and practically all works of construction are damaged greatly or destroyed. Disturbances in the ground are great and varied, and numerous shearing cracks develop. Landslides, rock falls, and slumps in river banks are numerous and extensive. Large rock masses are wrenched loose and torn off. Fault slips develop in firm rock, and horizontal and vertical offset displacements are notable. Water channels, both surface and underground, are disturbed and modified greatly. Lakes are dammed, new waterfalls are produced, rivers are deflected, etc. Surface waves are seen on ground surfaces. Lines of sight and level are distorted. Objects are thrown upward into the air.

07/19/16 5

MODIFIED MERCALLI INTENSITY SCALE

770632101


APPENDIX A

Borings, Laboratory Data and Cone Penetration TestsTreadwell & Rollo, Inc. Investigation for 2600 Tenth Street

DISTRIBUTION

1 copy: Mr. Richard RobbinsWareham Properties Group1120 Nye Street, Suite 400San Rafael, CA 94901

1 copy: Mr. Chris BarlowWareham Properties Group1120 Nye Street, Suite 400San Rafael, CA 94901

geotechnical investigation 1050 parker street berkeley ... · this report presents results of our...

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