a n k r - berkeley, california · 10/21/2016 · (sbt), which is interpreted by the cpt software...

October 13, 2016 2814-1A, L-30714

Mr. Rony Rolnisky 121 Devonshire Way San Francisco, CA 94131

RE: Geotechnical Investigation – Seismic Hazard Clarification 2527 San Pablo Avenue Berkeley, California

Dear Mr. Rolnisky:

At your request, we prepared this letter to clarify the seismic hazards evaluation for your project at 2527 San Pablo Avenue in Berkeley, California. We recently performed a geotechnical investigation for this site and presented our finding in the report titled “Geotechnical Investigation, 2527 San Pablo Avenue, Berkeley, California,” dated October 13, 2016.

It is our understanding that the City requested the geotechnical investigation report be completed in accordance with the “California Geologic Survey – Note 48” and/or the “Special Publication 117A.”

The California Geologic Survey – Note 48 is used by the California Geological Survey to review the geology, seismology, and geologic hazards evaluated in reports that are prepared under the California Code of Regulations (CCR), Title 24, California Building Code (2013 CBC). CCR Title 24 applies to California Public Schools, Hospitals, Skilled Nurse Facilities, and Essential Services Building. The proposed project is a residential/commercial mix building. Therefore, the California Geologic Survey – Note 48 does not apply.

The site has been mapped inside a zone of liquefaction potential on the map titled “State of California, Seismic Hazard Zones, Oakland West Quadrangle”, prepared by the California Geological Survey, dated February 14, 2003. The California Geological Survey has provided recommendations for geotechnical investigations performed within seismic hazard zones in Special Publication 117A (SP-117A), titled “Guidelines for Evaluating and Mitigating Seismic Hazard Zones in California”, dated September 11, 2008. Our geotechnical investigation and liquefaction evaluation generally followed the SP-117A recommendations.

The opinions and recommendations presented in this letter are made in accordance with generally accepted geotechnical engineering principles and practices. No other warranty, either expressed or implied, is made.

If you have any questions concerning this letter, please call us.

A L A N K R OP P & AS S O CI A T E S, I NC.

G E O T E C H N I C A L C O N S U L T A N T S

2140 Shattuck Avenue Berkeley, CA 94704 Tel 510.841.5095 Fax 510.841.8357 www.akropp.com

Alan Kropp, CE, GE

James R. Lott, CE, GE

Thomas M. Brencic, CE

Alma G. Luna, CE

Jose R. Serrano, CE

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Very truly yours, Alan Kropp, G.E. Alma Luna, C.E. Principal Engineer Project Engineer AL/AK/jc Copies: Addressee (PDF) – [email protected] 2814-1A 2527 San Pablo - Letter

GEOTECHNICAL INVESTIGATION 2527 SAN PABLO AVENUE BERKELEY, CALIFORNIA

October 13, 2016 2814-1A, L-30712

Mr. Rony Rolnizky 121 Devonshire Way San Francisco, CA 94131

RE: Geotechnical Investigation 2527 San Pablo Avenue Berkeley, California

Dear Mr. Rolnizky:

At your request, we have performed a geotechnical engineering investigation for the proposed new mixed-use building to be constructed at 2527 San Pablo Avenue in Berkeley, California. The approximate site coordinates (WGS84) for this location are 37.86048°N, 122.28927°W. The project location is shown on the Vicinity Map, Figure 1.

1.00 PROPOSED CONSTRUCTION

The site is currently occupied by a single-story structure and two small sheds that used to be an auto service station. Based on our discussions with you and our review of a preliminary conceptual layout for possible site development, it is our understanding the existing buildings are to be demolished to facilitate the construction a new six-story, mixed-use building with underground parking pits. The street level story will most likely be concrete construction (to be used as parking/retail space) and the upper five levels will be wood-framed construction (to be used as residential units). The below-grade parking pits may extend up to about 6 feet below the street level to accommodate parking stackers.

Plans or details for the proposed new building were not provided to us at the time of our investigation. However, building loads are anticipated to be typical for this type of construction based on buildings in the area having similar characteristics.

2.00 PURPOSE

The purpose of our investigation was to evaluate the suitability of the site for the proposed mixed-use building and to provide geotechnical engineering recommendations for the proposed work.

3.00 SCOPE

As outlined in our proposal dated September 27, 2016, the scope of our work to accomplish the stated purpose included:

A L A N K R OP P & AS S O CI A T E S, I NC.

G E O T E C H N I C A L C O N S U L T A N T S

2140 Shattuck Avenue Berkeley, CA 94704 Tel 510.841.5095 Fax 510.841.8357 www.akropp.com

Alan Kropp, CE, GE

James R. Lott, CE, GE

Thomas M. Brencic, CE

Alma G. Luna, CE

Jose R. Serrano, CE

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• A review of published geotechnical materials with data relevant to the site;

• A review of subsurface data by Stellar Environmental Solutions, Inc.;

• A reconnaissance of the site and portions of the immediate surrounding properties to evaluate

general geotechnical and site conditions;

• A field subsurface exploration program consisting of driving two Cone Penetrometer Tests (CPTs) at the site to evaluate the properties of the materials recovered;

• Geotechnical engineering analyses of the collected data; and

• Preparation of this geotechnical investigation report for the proposed development.

The scope of our services did not include an environmental assessment or investigation for the presence of hazardous or toxic materials in the soil, groundwater, or air on, below, or around the site. An evaluation of the potential presence of sulfates in the soil, or other corrosive, naturally occurring elements was beyond our scope. 4.00 SITE INVESTIGATION 4.01 Existing Geotechnical Data Review A variety of published materials were reviewed to evaluate geotechnical data relevant to the subject site. These sources included geotechnical literature, reports, and maps published by various public agencies. Maps which were reviewed included topographic, geologic, and preliminary photointerpretive landslide maps prepared by the United States Geological Survey, as well as geologic, landslide, and fault maps prepared by the California Geological Survey (formerly the California Division of Mines and Geology). A detailed citation of materials reviewed is presented in the References section at the end of this report. 4.02 Review of Subsurface Data by Stellar Environmental Solutions We were provided with a site environmental assessment by Stellar Environmental Solutions, Inc. (Stellar Environmental) which contained subsurface data from eleven site borings. A more detailed citation of the document reviewed is presented in the references section at the end of this report. 4.03 Surface Reconnaissance Visits A surface reconnaissance visit was performed on September 28, 2016. This visit was intended to make observations of surface conditions present, to note whether any obvious geotechnical concerns were exposed, and to mark the proposed CPT locations. 4.04 Subsurface Exploration

On October 3, 2016, we explored subsurface conditions at the site by advancing two CPT probes to depths between 48½ feet and 52 feet at the approximate locations shown on the Site Plan, Figure 2. California Push Technologies Inc. performed the CPT probes under the observation of an Alan Kropp & Associates engineer.

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The CPT method involves pushing a 2-inch-diameter conical probe into the ground using a hydraulic ram system. The CPT probe is equipped with sensors that produce a continuous record of tip resistance, sleeve friction and pore pressure as the cone is advanced. During cone advancement, real-time data obtained from the cone sensors are displayed on a computer monitor together with preliminary interpretive logs of soil type. During cone advancement, our engineer monitored the real-time cone data and determined the depths to which the probes would extend. California Push Technologies’ Report is attached in Appendix A. The CPT logs present graphical plots of cone resistance (qt), sleeve friction (fs), and pore water pressure (u), which are measured directly by the probe. Included on the logs is a graphical plot of friction ratio (Rf), a calculated parameter defined by the equation fs/qt x 100. The fifth column presents interpreted information pertaining to Soil Behavior Type (SBT), which is interpreted by the CPT software (CPeT-IT v.2.01.16), based on the calculated friction ratio, measured cone resistance, and published correlations (Robertson, 2009). 5.00 SITE CONDITIONS The topographic map for this area (the Oakland West Quadrangle) prepared by the United States Geological Survey indicates the site is located at an elevation of approximately 55 feet on the gently sloping flatland between the Berkeley Hills and the San Francisco Bay. A geologic map of the area by Radbruch (1957) indicates the site is underlain by the Temescal Formation. This formation is typically described as clayey gravel, sandy and silty clay, and sand-clay-silt mixtures of a pale to dark yellowish-orange color. Gravel in this unit consists of quartz, soft sandstone, shale, chert and other igneous rock fragments. The Temescal Formation covers most of the surface between the Berkeley Hills and the San Francisco Bay and is estimated to extend anywhere from 5 to 60 feet in thickness. A more recent geologic map by Graymer (2000) indicates the site is underlain by Holocene alluvial fan and fluvial deposits. The accompanying text of the map indicates this unit typically includes medium dense to dense, gravely sand or sandy gravel that generally grades upward to sandy or silty clay. A creeks and watershed map of the area by Sowers (2009) indicates that there is an underground culvert near the western edge of the site and the nearest creek is Potter Creek which formerly flowed about 2,000 feet south from the site toward the bay and which currently flows within an underground culvert below city streets. The California Geologic Survey has released a map covering this area which indicates areas (Seismic Hazard Zones) that may be prone to earthquake-induced ground failure (landsliding and/or liquefaction) during a major earthquake. The map (CGS, 2003) indicates areas where sufficient concern exists to merit a site-specific evaluation, not necessarily that the hazard is actually present. The site is located within the boundary of a State of California designated Seismic Hazard Zone (SHZ) for potential liquefaction hazards. The site is approximately 2.2 miles west of the nearest active trace of the Hayward fault (California Division of Mines and Geology, 1982; Lienkaemper, 1992). The site is also located about 16.4 miles east and 15.9 miles southwest of the active San Andreas and Concord faults, respectively (USGS, 2006). The site is not located within any Alquist-Priolo Earthquake Fault Zone designated by the State of California.

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5.01 Review of Geotechnical Data in the Immediate Site Vicinity We reviewed subsurface data in the immediate project vicinity obtained from our project files, other geotechnical consultants’ reports, and geologic literature. The data obtained indicates the typical soil profile in the immediate project vicinity consists of a layer of stiff, dark brown to black clay near the surface underlain by interbedded layers of very stiff to hard silty sandy and gravelly clays, and medium-dense to very dense clayey sands and clayey gravels, which extend to a depth greater than 40 feet. Groundwater was typically encountered at depths ranging from 7½ to 9 feet below the ground surface. Grain size analyses (fines content) conducted on samples of the sand materials indicate that these soils contain approximately 13% to 19% silt and clay size particles. The primary consideration for geotechnical design of projects in the immediate project vicinity was the presence of moderate to high expansion potential of the surficial clayey soils and the presence of high groundwater. The risk of liquefaction or other forms of dynamically induced ground failure was considered low. 5.02 Data from Previous Environmental Work at the Site We reviewed descriptions of subsurface materials encountered during the 2016 investigation conducted by Stellar Environmental for the soil, soil-gas, and groundwater investigation at the site. The following is a brief summary of some of the more pertinent observations and subsurface data contained in the documents:

• Two 4,000-gallon and two 6,000-gallon gasoline underground storage tanks (USTs) were removed from the southeast side of the service station in March 1989.

• In February 2016, eleven environmental borings were drilled at the site by Stellar Environmental to collect soil samples for an environmental study. The borings were drilled to a depth ranging from 4 to 24 feet. The approximate locations of the Stellar Environmental borings are indicated on the attached Site Plan, Figure 2. The boring logs are included in the attached Appendix B.

• In April 6, 2016, Stellar Environmental removed a 275-gallon waste oil UST from the site that was located on the north side of the service station. The excavation was backfilled with compacted class II recycled baserock.

5.03 Surface The site is roughly rectangular in shape with maximum plan dimensions of approximately 102 feet by 123 feet. The site is located at the northeast corner of the intersection of San Pablo Avenue and Blake Street. The property is bordered on the north and east by two-story residential buildings. The parcel at 2527 San Pablo Avenue is currently occupied by a single-story service building with an attached canopy, which is located on the central portion of the site and has plan dimensions of about 30 feet by 50 feet. Two small sheds are also located in the northeastern corner of the property. The rest of the site is currently a parking lot with asphalt driveways.

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A topographic survey shows that the terrain is relatively level with an approximate elevation of 53 feet. During our reconnaissance, no areas of major instability were observed in the vicinity of the proposed new building. 5.04 Subsurface 5.04.1 Stellar Environmental Borings The surficial materials encountered in the borings conducted by Stellar Environmental generally consisted of 6 to 12 feet of dark brown, stiff clays with a thin layer of loose sand and clayey sand. The surficial materials are underlain by interbedded stiff silty, sandy, and gravelly clay, and very dense gravel that extend to the maximum depth explored of about 24 feet. Borings B-8 and B-10 were drilled in areas where underground storage tanks and hydraulic hoist were previously removed. B-8 and B-10 encountered approximately 6 feet to 8 feet of sandy clay fill and gravel fill, respectively. Groundwater was encountered in B-1, B-8, and B-9 at an approximate depth ranging from 8 to 16 feet below existing grade and rose to an approximate depth of 5 to 6.5 feet shortly after drilling. 5.04.2 Alan Kropp and Associates (AKA) Cone Penetrometer Tests (CPTs) AKA advanced two CPTs at the site to an approximate depth of 48½ and 52 feet below the existing grade. CPT-1 was drilled along the northwest corner of the property and CPT-2 along the south side. The interpreted soil behavior encountered by the CPTs generally consisted of firm clays and silts in the upper 10 feet underlain by interbedded layers of stiff silt and clay and medium dense to dense sand and gravel. The native soils encountered by the CPTs are relatively consistent with materials observed at nearby locations during previous investigations Groundwater was observed at the site CPTs at an approximate depth of 13 to 14 feet below existing grade at the time of drilling. It should be noted that groundwater measurements in the CPTs may have been made prior to allowing the equilibrium groundwater conditions to become established. In addition, fluctuations in the groundwater level may occur due to variations in rainfall, temperature, and other factors not evident at the time the measurements were made. 6.00 EVALUATIONS AND CONCLUSIONS 6.01 General Site Suitability Based on our investigation, it is our opinion the site is suitable for the construction of the proposed mixed-use development from a geotechnical standpoint. However, all of the conclusions and recommendations presented in this report should be incorporated in the design and construction of the project to minimize possible geotechnical problems. The primary considerations for geotechnical design at the site are:

• Liquefaction potential;

• The shrink/swell behavior of the surficial soils;

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• The presence of existing fill soils at the site;

• Groundwater considerations;

• Excavations and temporary shoring;

• Earthquake hazards; and

• Foundation selection.

Each of these conditions is discussed individually below. 6.02 Liquefaction Potential Liquefaction is the transformation of a deposit of soil from a solid state to a liquefied state as a consequence of increased pore pressure and reduced effective stress. Often, this transformation results from the cyclic loading of an earthquake and the soil acquires “mobility” sufficient to permit both horizontal and vertical movements. Soils that are most susceptible to liquefaction are clean, loose, saturated (below groundwater), and uniformly graded fine-grained sands. The vast majority of liquefaction hazards are associated with sandy soils and silty soils of low plasticity. Cohesive soils are generally not considered susceptible to soil liquefaction. In the CPT-based analyses, soil behavior types (e.g. sand, silt, and clay) are interpreted based on the measured values of cone tip resistance, sleeve friction, and pore pressure. Under the procedures outlined by Roberson & Wride (1998) and Robertson (2009), “soil behavior types” (SBT) are obtained using a logarithmic plot of normalized friction ratio versus normalized cone resistance. On this plot, the boundaries of the soils behavior types are approximated by concentric circles, the radius of these circles are used as a soil type index (Ic). Ic values less than 2.6 are considered predominantly granular in nature and materials with Ic values greater than 2.6 are generally considered “too clayey” to liquefy. We evaluated liquefaction potential based on the two CPT data using the software Cliq (v.2.06.82) by Geologismiki, which utilizes the methodology outlined by Youd et al., 2001, Robertson, 2009, and Idriss & Boulanger, 2014 (among others). This method involves assessing the seismic demand on a soil layer, expressed in terms of the cyclic stress ratio (CSR), and comparing this value to the capacity of the soil to resist liquefaction, expressed in terms of the cyclic resistance ratio (CRR). The factor of safety against liquefaction is determined by dividing the CRR by the CSR. Soils having a factor of safety less than or equal to 1.0 are considered liquefiable. To account for fluctuations in groundwater levels due to variations in rainfall, temperature, and other factors, we used a groundwater depth of 5 feet (below the ground surface) in our liquefaction analyses. Estimates of in-place density were obtained directly from the interpretive CPT data provided by California Push Technologies. Levels of ground shaking used in our analyses were based on an earthquake moment magnitude (MW) of 7.1 with site-modified peak ground acceleration (PGAm) of 0.767g. We note that these values were obtained from published data (USGS and CGS) and not from a site-specific probabilistic seismic hazards assessment.

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Our CPTs encountered relatively thin and discontinuous liquefiable layers which varied in thickness between depths of about 6 and 51 feet below the ground surface. Our study shows that the areas analyzed typically result in settlements between about 1 to 2 inches. Differential settlement between adjacent foundations could be on the order of ⅔ of the total settlement. In order to minimize the detrimental impacts of liquefaction-induced settlement, we recommend that the proposed building be supported on a relatively strong and well tied together foundation, such as could be accomplished with a rigid mat foundation. Our liquefaction analysis report for CPT-1 and CPT-2 are included in Appendix C. The total vertical settlement results are shown on the fifth plots on page 5 of each of the two reports. 6.03 Expansive Surficial Soils Based on laboratory data from 2577 San Pablo Avenue, the surficial clay soils in the site vicinity are moderately to highly expansive, and are prone to significant volume changes (shrinkage and swelling) with seasonal fluctuations in soil moisture. Such shrink/swell behavior can damage shallow foundation elements or other elements located directly on them such as sidewalks and driveways. To help minimize tilting and cracking of these we recommend they be underlain by a layer of imported, non-expansive material and compacted in accordance with the compaction recommendations provided in Section 7.01.5. 6.04 Existing Fill The proposed new building footprint is underlain by two areas of old tank backfill, the degree of compaction of which is undocumented. Based on the results of the subsurface exploration by Stellar Environmental, the fill thickness in these areas appears to be in the order of 6 feet to 8 feet. The proposed excavations for the parking pits are anticipated to be in the order of 8 feet and will likely extend through the fill layer. However, we recommend that a representative from our firm should observe the building subgrade and the bottom of all foundation excavations to confirm if the material exposed appears to be adequate for construction. Any fill material encountered during construction that is not excavated or deemed to be adequate should be removed and excavations backfilled with compacted engineered fill placed in accordance with the recommendations provided in this report. 6.05 Groundwater Considerations Groundwater was encountered in the borings (B-1, B-8, and B-9) drilled by Stellar Environmental at approximately 8 to 16 feet during drilling and it was measured at about 5 to 8 feet before grouting. The two CPTs drilled for this investigation groundwater was measured at an approximate depth of 13 feet to 14 feet below existing grade. Data from the nearby sites indicates groundwater levels were observed to rise to a depth of 7½ to 9 feet below existing grade. Considering that our subsurface exploration was completed in early October of one of the driest years in the history of California, the observed groundwater may be at the lower end of any anticipated range of seasonal fluctuations. Based upon the information obtained in our subsurface exploration, we judge that a design groundwater level at 5 feet below the existing grade may be used for design purposes. We understand that excavations for the parking garage will extend to a depth of approximately 8 feet below grade. The contractor should be made aware of the potential for high groundwater and a temporary

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de-watering method during construction may still become necessary. Temporary construction dewatering methods may include sumps and pumps placed in a low spot within the excavations. Several sumps and pumps may be required depending on the magnitude of water encountered. The design and implementation of temporary construction de-watering is considered the responsibility of the contractor. Caution should be exercised to prevent softening of the subgrade soils exposed within the excavations. Equipment operated upon saturated subgrade soils tends to cause rutting and weakening, which will require over-excavation of the weakened subgrade. Standing water within the excavation can also cause weakening of the subgrade soils. A temporary mud slab or gravel pad may needed at the base of the garage and/or parking lifts excavations to provide a clean, dry working area. Given the potential for an increase in the groundwater level over the life of the building, we recommend the parking pits be design to resist lateral and uplift hydrostatic pressures and appropriate waterproofing of the walls and floor be installed. A waterproofing expert should be consulted to provide recommendations. 6.06 Excavations and Temporary Shoring Excavations of up to 8 feet below existing grade are anticipated as part of this project. Excavation may be sloped back at inclinations not steeper than 1:1. However, temporary shoring and/or underpinning should be implemented by the contractor to protect adjacent improvements during site excavations, as necessary. Existing improvement that may be affected by the proposed development include, but are not limited to, adjacent structures, sidewalks, curbs, pavements, and underground utilities. The contractor is responsible for installation and performance of all shoring and underpinning measures. 6.07 Building Foundation The current proposed development will consist of a six-story, mixed-use retail/residential building with some below-grade parking pits. Based on the results of our investigation, and the potential for settlement due to earthquake-induced liquefaction, as well as new building loads, we recommend that the proposed building be supported on a foundation system consisting of a reinforced concrete mat foundation. Where foundation elevations are near or below the design groundwater level and drainage provisions do not provide for lowering of groundwater within the structure footprint, foundation and floor will be subjected to hydrostatic uplift forces. Hydrostatic uplift can be resisted by a combination of the weight of the structure itself and structural hold-downs. 6.08 Earthquake Hazards As noted earlier, the subject site is located in the highly seismic San Francisco Bay Area, and there is a strong probability that a moderate to severe earthquake will occur during the life of the structure. The site is not mapped in the immediate proximity of any active or inactive faults; therefore, the likelihood of fault rupture directly below the proposed home is very remote. The proposed development will very likely experience strong ground shaking during a major earthquake in the life of the structure. The California Building Code has adopted provisions for incorporation of strong ground shaking into the design of all structures. Our recommendations for geotechnical parameters to be used in the structural design for the project are presented in Section 7.06, “California Building Code Seismic Design Parameters”.

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7.00 RECOMMENDATIONS It is the responsibility of you or your representative to confirm that the recommendations presented in this report are called to the attention of the contractor, subcontractors, and any governmental body which may have jurisdiction and that these recommendations are carried out in the field. 7.01 Site Preparation and Earthwork 7.01.1 Clearing and Site Preparation The site should initially be cleared of selected surface and subsurface obstructions including existing foundations. Underground utilities that interfere with the proposed construction should be re-routed or abandoned. Holes resulting from the removal of underground obstructions extending below the proposed finished grade should be cleared and backfilled with suitable materials compacted in accordance with our recommendations presented in Section 7.01.5, “Compaction”. 7.01.2 Excavations and Shoring As previously mentioned, it appears that excavations for the parking pits at the site will extend to a depth of approximately 8 feet below existing grade. Due to the depth of the anticipated parking pits excavations, the proximity of existing adjacent improvements to the site, and the potential for presence of relatively shallow groundwater at the site, it is anticipated that temporary shoring will be required for this project. Temporary shoring should be used as required to prevent the movement of materials exposed in the face of the excavations. We recommend the excavations and subsequent parking pit construction be continuous in order to minimize the length of time the excavations is exposed. However, since we have no control over the methods and timing used by the contractor, the stability of any excavation is solely the responsibility of the contractor. It is, however, recommended that our firm review the shoring plans in order to evaluate the potential interaction between the temporary shoring and the permanent structure. 7.01.3 Subgrade Preparation Following site preparation and completion of proposed excavations, a representative of our firm should observe the base of the excavations to determine if problematic areas exist. The exposed soils in those areas to receive structural fill, slabs-on-grade, or mats should be firm, unyielding, and compacted to the requirements for structural fill. Soft or yielding subgrade soils should be excavated to expose firm, non-yielding materials. Proof–rolling may be helpful in identifying soft or yielding subgrade areas. The subgrade soils should be scarified to a depth of 6 inches. The scarified soils should them be moisture conditioned to at least 3 percent above optimum water content and compacted to the specified relative compaction. It is possible that exposed subgrade soils may be excessively wet or dry depending on the moisture content at the time of construction. If the subgrade soils are too wet, they may be dried by aeration, mixing with drier materials, or lime/cement treatment.

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7.01.4 Material for Fill On-site soils below the cleared site having an organic content of less than 3 percent by volume are suitable for use as fill except in areas where specific fill materials are recommended. Fill placement at the site should not contain rocks or lumps greater than 6 inches in greatest dimension with not more than 15 percent larger than 2.5 inches. In addition, imported select fill used at the site should be a non-expansive material with a plasticity index of 15 or less. 7.01.5 Compaction Clayey soils should be moisture conditioned to at least 3 percent over optimum water content and compacted to at least 90 percent relative compaction by mechanical means only as determined by ASTM Test Designation D1557 (latest revision). Sandy soils should be moisture conditioned to near optimum water content and compacted to at least 95 percent relative compaction. The upper 6 inches of subgrade soils and base rock materials should be compacted to at least 95 percent relative compaction. Fill should be placed on a firm, unyielding surface in lifts not exceeding 8 inches in uncompacted thickness. 7.01.6 Trench Backfill Pipeline trenches should be backfilled with fill placed in lifts not exceeding 8 inches in uncompacted thickness. Native backfill materials should be compacted to at least 90 percent relative compaction and granular import material should be compacted to at least 95 percent relative compaction. These compaction recommendations assume a reasonable “cushion” layer around the pipe. If imported granular soil is used, sufficient water should be added during the trench backfilling operations to prevent the soil from “bulking” during compaction. 7.02 Mat Slab Foundation We recommend that the new building be supported on a reinforced concrete mat slab foundation system. The mat slab should be a minimum of 24 inches thick and the base of the mat slab should extend at least 12 inches below the adjacent ground surface. The mat can be designed assuming an allowable bearing pressure of 1,000 pounds per square foot for dead plus live loads, with a one-third increase for all loads including wind or seismic. This allowable bearing pressure is a net value; therefore, the weight of the mat can be neglected for design purposes. The mat should be integrally connected to all portion of the structure so the entire foundation system moves as a unit. The mat should be reinforced with top and bottom steel in both directions to allow the foundation to span local irregularities that may result from potential differential settlement. As a minimum, we recommend that the mat be reinforced with sufficient top and bottom steel to span as a simple beam an unsupported distance of at least 10 feet. The mat can be designed using a modulus of subgrade reaction, Kv1, of 100 kips per cubic foot. Lateral loads on the structure may be resisted by passive pressures acting against the sides of the mat. We recommend an allowable passive pressure equal to an equivalent fluid weighing 300 psf per foot of depth (factor of safety ≈ 2). Alternatively, an allowable friction coefficient of 0.20 (factor of safety ≈ 2) can be used between the bottom of the mat and the subgrade soils. If the perimeter of the mat is poured neat against the soils, the passive pressure and friction coefficient may be used in combination.

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In order to minimize vapor transmission, a vapor retardant membrane (Class A vapor retarder [ASTM E1745, latest revision]) should be placed beneath the mat. The membrane should be covered with 2 inches of sand to protect it during construction. The sand should be lightly moistened just prior to placing the concrete. In order to reduce potential infiltration into the sand layer, the sand should be terminated approximately 12 inches from the perimeter edge of the mat and the mat should be thickened by 2 inches to compensate for the elimination of the sand layer. Any tears in the retarder and all plumbing penetrations should be sealed with an appropriate taping material. If the vapor retarder is upgraded to a more substantial material (such as Stego Wrap 15-mil or approved equivalent), consideration could be given to eliminate the 2-inch sand layer. Where the mat will be surfaced with flooring material, we recommend that the specifications for the mat require moisture emission tests to be performed on the mat prior to the installation of the flooring. No flooring should be installed until safe moisture emission levels are recorded for the type of flooring to be used. 7.03 Exterior Slabs on Grade Exterior slabs-on-grade underlain by moderately to highly expansive surficial soils should be supported on a minimum of 12 inches of imported, compacted, non-expansive fill. The surficial soils beneath the non-expansive fill should scarified to a depth of at least 6 inches, moisture conditioned, and compacted in accordance with compaction recommendations presented in Section 7.01.5. 7.04 Retaining Walls Retaining walls should be designed to resist both lateral earth pressures and any additional lateral loads caused by surcharge loads on the adjoining ground surface. Undrained retaining walls should be designed to resist lateral earth pressures, hydrostatic loads, surcharge loads, and seismic loading. We recommend walls be designed using an equivalent fluid pressure (not including surcharge loading) of 60 pounds per cubic foot (pcf) above the groundwater level and 95 pcf below the groundwater level. For retaining wall design, we recommend assuming a design groundwater depth of 5 feet below the currently existing grade. Basement walls 6 feet or greater in height should also be designed for a temporary seismic load. The temporary seismic load can be modeled as a uniform lateral pressure applied over the height of the wall of 10H psf, where H is the height in feet. The provisional recommendations for seismic earth pressures on building basement wall, as provided by Lew, et al. (2010), were considered in development of the seismic load criteria given. The values given above assume level backfill behind the wall with no surcharge loads. For additional surcharge loads, such as heavy slab loads, concentrated loads, or vehicular loading; design pressures should be increased by an additional uniform pressure equivalent to one-half of the maximum anticipated surcharge load applied to the surface behind the wall. Structural backfill placed behind the retaining wall should be compacted in accordance with the requirements provided in Section 7.01.5. Retaining walls should be supported on mat slab foundations designed in accordance with Section 7.02, “Mat Slab Foundation”.

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7.05 Surface Drainage We recommend that collected surface water be transmitted through gutters and downspout to closed pipes that discharge to an appropriate discharge facility. Flexible pipe (flexline), 2,000-pound crush pipe, leachfield, and ASTM F810 pipe are NOT recommended for use in these drainage systems because of the likelihood of damage to the pipe during installation due the weak strength of these pipes. In addition, these drainpipes are sometime difficult to clean with mechanical equipment without damaging the pipe. We recommend the use of Schedule 40 PCV, SDR 35 PVC or ABS, Contech A-2000 PCV drainpipe, or approved equivalent for the drain system. Positive surface gradient of at least 2 percent should be provided adjacent to the structure to direct water away from the foundations and slabs toward a suitable discharge facility. Ponding of surface water should not be allowed adjacent to the structure or on pavements. The project civil engineer should develop the provisions necessary to conform to current city/county regulations. Such measures may include retention basins, grassy swales, or other provisions, which may allow some water to eventually flow onto the street and into nearby inlet leading to the storm drain systems. We should note that suitable discharge facilities do not include so called “dry wells” and these should be avoided. 7.06 California Building Code Seismic Design Parameters Based on our review of the site location, assumed soil conditions, and the 2013 California Building Code (CBC), we recommend the following parameters be used for seismic design of the building:

• Site Class = D • Mapped Spectral Acceleration for Short Period (SS, Site Class B) = 1.992g • Mapped Spectral Acceleration for 1-Second Period (S1, Site Class B) = 0.810g • Maximum Considered Earthquake (MCE) Spectral Response Acceleration for Short Period (SMS,

Site Class D) = 1.992g • MCE Spectral Response Acceleration for 1-Second Period (SM1, Site Class D) = 1.215g • Design Spectral Response Acceleration for Short Period (SDS, Site Class D) = 1.328g • Design Spectral Response Acceleration for 1-Second Period (SD1, Site Class D) = 0.810g

7.07 Supplemental Recommendations As previously mentioned, at the time of our investigation project plans or detail had not been developed. Once the project layout and dimensions are established supplemental recommendations may be necessary. If necessary, please contact us when near final plans have been completed. 7.08 Plan Review We recommend our firm be provided the opportunity for a general review of the geotechnical aspects of the final plans and specifications for this project in order that the geotechnical recommendations may be properly interpreted and implemented. If our firm is not accorded the privilege of making the recommended review, we can assume no responsibility for misinterpretation of our recommendations.

2814-1A

7.09 Construction Observation The analyses and recommendations submitted in this report are based in part upon the data obtained from the two CPTs advanced for this study and eleven borings by Stellar Environmental. The nature and extent of variations across the site may not become evident until construction. If variations then become apparent, it will be necessary to re-examine the recommendations of this report. We recommend our firm be retained to provide geotechnical engineering services during the earthwork, foundation construction, and drainage phases of the work. This is to observe compliance with the design concepts, specifications, and recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to the start of construction. It should be noted that earthwork and foundation observations by our firm, as the project geotechnical engineer of record, are required by most cities and counties. Drainage observations by our firm are not typically required, but in our experience, we have often discovered adverse drainage installations that otherwise would have created problems following construction, and this is why we recommend our services be utilized. Nonetheless, it is usually the owner's prerogative whether they wish to engage our services or simply rely on the quality of their contractor's work regarding drainage improvements. In order to effectively accomplish our observations during the project construction, we recommend that a pre-construction meeting be held to develop a mechanism for proper communications throughout the project. We also request that the client or the client's representative (the contractor) contact our firm at least two working days prior to the commencement of any of the items listed above. If our representative makes a site visit in response to a request from the client or the client's representative and it turns out that the visit was not necessary, our charges for the visit will still be forwarded to the client. 7.10 Wet Weather Construction Although it is possible for construction to proceed during or immediately following the wet winter months, a number of geotechnical problems may occur which may increase costs and cause project delays. The water content of on-site soils may increase during the winter and rise significantly above optimum moisture content for compaction of subgrade or backfill materials. If this occurs, the contractor may be unable to achieve the recommended levels of compaction without using special measures and would likely have to:

• Wait until the materials are dry enough to become workable;

• Dispose of the wet soils and import dry soils; or

• Use lime or cement on the native materials to absorb water and achieve workability.

If utility trenches or excavations are open during winter rains, then caving of the trenches or excavations may occur. Also, it the trenches fill with water during construction, or if saturated materials are encountered at the anticipated bottom of the excavations, excavations may need to be extended to greater depths to reach adequate support capacity than would be necessary if dry weather construction took place.

We should also note that it has been our experience that increased clean-up costs will occur, and greater safety hazards will exist, if the work proceeds during the wet winter months. Furthermore, engineering costs to observe construction are increased because of project delays, modifications, and rework.

2814-1A

8.00 REPORT LIMITATIONS AND CLOSURE

This report has been prepared for the exclusive use of you and your consultants for specific application to the subject site in accordance with generally accepted geotechnical engineering practice. No other warranty, either expressed or implied, is made. In the event the nature, design, or location of the project differs significantly from what has been noted above, the conclusions and recommendations contained in this report should not be considered valid unless the changes are reviewed and the conclusions of this report modified or verified in writing.

The findings of this report are valid as of the present date. However, the passing of time will likely change the conditions of the existing property due to natural processes or the work of man. In addition, due to legislation or the broadening of knowledge, changes in applicable or appropriate standards may occur. Accordingly, the findings of this report may be invalidated, wholly or partly, by changes beyond our control. Therefore, this report should not be relied upon after three years without being reviewed by this office.

If you have any questions concerning this letter, please call us.

Very truly yours,

Alan Kropp, G.E. Alma Luna, C.E. Principal Engineer Project Engineer

AL/AK/jc

Copies: Addressee (PDF) – [email protected]

2814-1A 2527 San Pablo GI Report

2814-1A

REFERENCES

Published Data California Division of Mines and Geology, 1982, Special Studies Zone Map, Oakland West Quadrangle. California Geological Survey, 2003, “Seismic Hazard Zone Report of the Oakland West 7.5-Minute Quadrangle, Alameda County, California,” Seismic Hazards Zone Report 081. Graymer, R.W., 2000, “Geologic Map and Map Database of the Oakland Metropolitan Area, Alameda, Contra Costa and San Francisco Counties, California” U.S. Geological Survey, Miscellaneous Field Studies MF-2342. Lew, M., Sitar, N., Atik, L., Pourzanjani, M., Hudson, M., 2010, “Seismic Earth Pressures on Deep Building Basements,” SEAOC 2010 Convention Proceedings. Lienkaemper, J. J., 1992, “Map of Recently Active Traces of the Hayward Fault, Alameda and Contra Costa Counties, California,” United States Geological Survey, Map MF-2196. Radbruch, Dorothy H., 1957, “Areal and Engineering Geology of the Oakland West Quadrangle,” U.S. Geological Survey, Miscellaneous Geologic Investigations, Map I-239. Robertson, P.K., 2009, “Interpretation of Cone Penetration Tests – a unified approach,” Canadian Geotechnical Journal, Vol. 46, No. 11: 1337-1355. Robertson, P.K. and Wride, C.E., 1998, “Evaluating Cyclic Liquefaction Potential Using the Cone Penetration Test,” Canadian Geotechnical Journal 35: 442-459. Sowers, Janet M., 1993, “Creek & Watershed Map of Oakland & Berkeley,” Oakland Museum of California. Revised 2010. U.S. Geological Survey, 1959, Topographic Map of the Oakland West Quadrangle. Photorevised 1968, 1973 and 1980. U.S. Geological Survey and California Survey, 2006, Quaternary fault and fold database for the United States, accessed October 17, 2008, from USGS web site:http//earthquake.usgs.gov/hazards/qfaults/. Witter, Robert C., et al., 2006, “Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California,” U.S. Geological Survey, Open File Report 2006-1037. Youd, T.L. and Idriss, I.M., 2001, “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils,” ASCE, Journal of Geotechnical and Geoenvironmental Engineering, April 2001. Unpublished Reports Alan Kropp & Associates, 2002, titled “Geotechnical Investigation, Proposed Building, 2577 San Pablo Avenue, Berkeley, California,” prepared for Mr. Todd Harvey, dated July 2, 2012, Job Number 2196-1.

2814-1A

Stellar Environmental Solutions, Inc., 2016, titled “Phase II Subsurface Investigation, 2527 San Pablo Avenue, Berkeley, California,” prepared for Rony Rolinsky, dated February 2016.

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Original figure produced in color.

PROJECT NO. DATEFIGURE 1

2814-1A October 2016

2527 SAN PABLO AVENUE

Berkeley, California

VICINITY MAPALAN KROPP& ASSOCIATES

Geotechnical

Consultants

When making a vicinity map:

Open the Thomas Brothers digital map

Search for your address

Zoom to zoom 7

Print using Adobe PDF or PDF 995 as your printer

Set the paper size to 11x17, landscape - save in drafted figures folder

Open the Master 2009 Vicinity Map file in illustrator

File -> Place, browse for the Thomas Brother pdf

Rotate the pdf - right click on image, Transform, Rotate (usually 270 degrees)

Scale the PDF - right click on image, Transform, Scale - 99.1%

Send the TB map to the back - Edit -> Cut, Edit -> Paste in Back

Select both the map and the rectangle on the screen,

Make a clipping mask, Right click, Make clipping mask

Put it on layer 2 - Edit Cut, Select layer 2, Edit Paste in Back

Move the site identifiier (star, circle, etc.) to the correct location

Update Job Name, number and date

Print Page

When the map is printed, check the scale

SITE

01000 1000 2000

APPROXIMATE SCALE (FEET)

Source: 2009 Thomas Brothers Maps

Bla

ke S

treet

San Pablo Avenue

SITE PLAN2527 SAN PABLO AVENUE

Berkeley, California

PROJECT NO. DATE2814-1A October 2016

FIGURE 2

Source: "2527 San Pablo Avenue" drawn by Rony RolnizkyArchitect, dated May, 31 2016.

LEGEND

Approximate location of exploratory boring (Stellar Environmental Solutions, 2016)

Approximate location of CPT (This Study)

Approximate location of Underground Tank Removed (Stellar Environmental Solutions, 2016)

APPROXIMATE SCALE FEET

10 0 20 40

APPENDIX A CPT REPORT BY CALIFORNIA PUSH TECHNOLOGIES

PRESENTATION OF SITE INVESTIGATION RESULTS

2527 San Pablo

Prepared for:

Alan Kropp & Associates

CPT Inc. Job No: 16-56073 --

Project Start Date: 03-Oct-2016 Project End Date: 03-Oct-2016

Report Date: 04-Oct-2016

Prepared by:

California Push Technologies Inc.

820 Aladdin Avenue San Leandro, CA 94577

- Tel: (510) 357-3677

Email: [email protected]

www.cptinc.com

http://www.cptinc.com/

2527 San Pablo

Introduction The enclosed report presents the results of the site investigation program conducted by CPT Inc. for Alan Kropp & Associates at 2527 San Pablo Avenue, Berkeley, CA. The program consisted of two cone penetration tests (CPT). Project Information

Project

Client Alan Kropp & Associates

Project 2527 San Pablo

CPT Inc. project number 16-56073

A map from Google earth including the CPT test locations is presented below.

Rig Description Deployment System Test Type

CPT Truck Rig (C15) 30 ton rig cylinder CPT

2527 San Pablo

Coordinates

Test Type Collection Method EPSG Reference

CPT Consumer Grade GPS 32610

Cone Penetration Test (CPT)

Depth reference Depths are referenced to the existing ground surface at the time

of each test.

Tip and sleeve data offset 0.1 meter

This has been accounted for in the CPT data files.

Additional plots Advanced CPT plots with Ic, Su(Nkt) and N1(60).

Cone Penetrometers Used for this Project

Cone Description Cone

Number

Cross

Sectional Area

(cm2)

Sleeve

Area

(cm2)

Tip

Capacity

(bar)

Sleeve

Capacity

(bar)

Pore

Pressure

Capacity

(psi)

443:T1500F15U500 443 15 225 1500 15 500

Cone 443 was used for all CPT soundings.

Interpretation Tables

Additional information

The Soil Behaviour Type (SBT) classification chart (Robertson et al., 1986) was used to classify the soil for this project. A detailed set of CPT interpretations were generated and are provided in Excel format files in the release folder. The CPT interpretations are based on values of corrected tip (qt), sleeve friction (fs) and pore pressure (u2).

Soils were classified as either drained or undrained based on the Soil Behaviour Type (SBT) classification chart (Robertson et al., 1986). Calculations for both drained and undrained parameters were included for materials that classified as silt (zone 6).

2527 San Pablo

Limitations This report has been prepared for the exclusive use of Alan Kropp & Associates (Client) for the project titled “2527 San Pablo”. The report’s contents may not be relied upon by any other party without the express written permission of CPT Inc. CPT Inc. has provided site investigation services, prepared the factual data reporting, and provided geotechnical parameter calculations consistent with current best practices. No other warranty, expressed or implied, is made. The information presented in the report document and the accompanying data set pertain to the specific project, site conditions and objectives described to CPT Inc. by the Client. In order to properly understand the factual data, assumptions and calculations, reference must be made to the documents provided and their accompanying data sets, in their entirety.

CONE PENETRATION TEST

The cone penetration tests (CPTu) are conducted using an integrated electronic piezocone penetrometer and data acquisition system manufactured by Adara Systems Ltd. of Richmond, British Columbia, Canada. CPT Inc.’s piezocone penetrometers are compression type designs in which the tip and friction sleeve load cells are independent and have separate load capacities. The piezocones use strain gauged load cells for tip and sleeve friction and a strain gauged diaphragm type transducer for recording pore pressure. The piezocones also have a platinum resistive temperature device (RTD) for monitoring the temperature of the sensors, an accelerometer type dual axis inclinometer and a geophone sensor for recording seismic signals. All signals are amplified down hole within the cone body and the analog signals are sent to the surface through a shielded cable. The penetrometers are manufactured with various tip, friction and pore pressure capacities in both 10 cm2 and 15 cm2 tip base area configurations in order to maximize signal resolution for various soil conditions. The specific piezocone used for each test is described in the CPT summary table presented in the first appendix. The 15 cm2 penetrometers do not require friction reducers as they have a diameter larger than the deployment rods. The 10 cm2 piezocones use a friction reducer consisting of a rod adapter extension behind the main cone body with an enlarged cross sectional area (typically 44 mm diameter over a length of 32 mm with tapered leading and trailing edges) located at a distance of 585 mm above the cone tip. The penetrometers are designed with equal end area friction sleeves, a net end area ratio of 0.8 and cone tips with a 60 degree apex angle. All piezocones can record pore pressure at various locations. Unless otherwise noted, the pore pressure filter is located directly behind the cone tip in the “u2” position (ASTM Type 2). The filter is 6 mm thick, made of porous plastic (polyethylene) having an average pore size of 125 microns (90-160 microns). The function of the filter is to allow rapid movements of extremely small volumes of water needed to activate the pressure transducer while preventing soil ingress or blockage. The piezocone penetrometers are manufactured with dimensions, tolerances and sensor characteristics that are in general accordance with the current ASTM D5778 standard. Our calibration criteria also meet or exceed those of the current ASTM D5778 standard. An illustration of the piezocone penetrometer is presented in Figure CPTu.


Figure CPTu. Piezocone Penetrometer (15 cm2)

The data acquisition systems consist of a Windows based computer and a signal conditioner and power supply interface box with a 16 bit (or greater) analog to digital (A/D) converter. The data is recorded at fixed depth increments using a depth wheel attached to the push cylinders or by using a spring loaded rubber depth wheel that is held against the cone rods. The typical recording intervals are either 2.5 cm or 5.0 cm depending on project requirements; custom recording intervals are possible. The system displays the CPTu data in real time and records the following parameters to a storage media during penetration:

Depth

Uncorrected tip resistance (qc)

Sleeve friction (fs)

Dynamic pore pressure (u)

Additional sensors such as resistivity, passive gamma, ultra violet induced fluorescence, if applicable

All testing is performed in accordance to CPT Inc.’s CPT operating procedures which are in general accordance with the current ASTM D5778 standard.


Prior to the start of a CPTu sounding a suitable cone is selected, the cone and data acquisition system are powered on, the pore pressure system is saturated with either glycerin or silicone oil and the baseline readings are recorded with the cone hanging freely in a vertical position. The CPTu is conducted at a steady rate of 2 cm/s, within acceptable tolerances. Typically one meter length rods with an outer diameter of 1.5 inches are added to advance the cone to the sounding termination depth. After cone retraction final baselines are recorded. Additional information pertaining to CPT Inc.’s cone penetration testing procedures:

Each filter is saturated in silicone oil or glycerin under vacuum pressure prior to use

Recorded baselines are checked with an independent multi-meter

Baseline readings are compared to previous readings

Soundings are terminated at the client’s target depth or at a depth where an obstruction is encountered, excessive rod flex occurs, excessive inclination occurs, equipment damage is likely to take place, or a dangerous working environment arises

Differences between initial and final baselines are calculated to ensure zero load offsets have not occurred and to ensure compliance with ASTM standards

The interpretation of the piezocone data and associated calculated parameters for this report are based on the corrected tip resistance (qt), sleeve friction (fs) and pore water pressure (u). The interpretation of soil type is based on the correlations developed by Robertson (1990) and Robertson (2009). It should be noted that it is not always possible to accurately identify a soil type based on these parameters. In these situations, experience, judgment and an assessment of other parameters may be used to infer soil behavior type. The recorded tip resistance (qc) is the total force acting on the piezocone tip divided by its base area. The tip resistance is corrected for pore pressure effects and termed corrected tip resistance (qt) according to the following expression presented in Robertson et al, 1986:

qt = qc + (1-a) • u2

where: qt is the corrected tip resistance qc is the recorded tip resistance u2 is the recorded dynamic pore pressure behind the tip (u2 position) a is the Net Area Ratio for the piezocone (0.8 for CPT Inc. probes)

The sleeve friction (fs) is the frictional force on the sleeve divided by its surface area. As all CPT Inc. piezocones have equal end area friction sleeves, pore pressure corrections to the sleeve data are not required. The dynamic pore pressure (u) is a measure of the pore pressures generated during cone penetration. To record equilibrium pore pressure, the penetration must be stopped to allow the dynamic pore pressures to stabilize. The rate at which this occurs is predominantly a function of the permeability of the soil and the diameter of the cone.


The friction ratio (Rf) is a calculated parameter. It is defined as the ratio of sleeve friction to the tip resistance expressed as a percentage. Generally, saturated cohesive soils have low tip resistance, high friction ratios and generate large excess pore water pressures. Cohesionless soils have higher tip resistances, lower friction ratios and do not generate significant excess pore water pressure. A summary of the CPTu soundings along with test details and individual plots are provided in the appendices. A set of files with calculated geotechnical parameters were generated for each sounding based on published correlations and are provided in Excel format in the data release folder. Information regarding the methods used is also included in the data release folder. For additional information on CPTu interpretations and calculated geotechnical parameters, refer to Robertson et al. (1986), Lunne et al. (1997), Robertson (2009), Mayne (2013, 2014) and Mayne and Peuchen (2012).

PORE PRESSURE DISSIPATION TEST

The cone penetration test is halted at specific depths to carry out pore pressure dissipation (PPD) tests, shown in Figure PPD-1. For each dissipation test the cone and rods are decoupled from the rig and the data acquisition system measures and records the variation of the pore pressure (u) with time (t).

Figure PPD-1. Pore pressure dissipation test setup

Pore pressure dissipation data can be interpreted to provide estimates of ground water conditions, permeability, consolidation characteristics and soil behavior.

The typical shapes of dissipation curves shown in Figure PPD-2 are very useful in assessing soil type, drainage, in situ pore pressure and soil properties. A flat curve that stabilizes quickly is typical of a freely draining sand. Undrained soils such as clays will typically show positive excess pore pressure and have long dissipation times. Dilative soils will often exhibit dynamic pore pressures below equilibrium that then rise over time. Overconsolidated fine-grained soils will often exhibit an initial dilatory response where there is an initial rise in pore pressure before reaching a peak and dissipating.


Figure PPD-2. Pore pressure dissipation curve examples

In order to interpret the equilibrium pore pressure (ueq) and the apparent phreatic surface, the pore pressure should be monitored until such time as there is no variation in pore pressure with time as shown for each curve of Figure PPD-2. In fine grained deposits the point at which 100% of the excess pore pressure has dissipated is known as t100. In some cases this can take an excessive amount of time and it may be impractical to take the dissipation to t100. A theoretical analysis of pore pressure dissipations by Teh and Houlsby (1991) showed that a single curve relating degree of dissipation versus theoretical time factor (T*) may be used to calculate the coefficient of consolidation (ch) at various degrees of dissipation resulting in the expression for ch shown below.

ch=T*∙a2∙√Ir

t

Where: T* is the dimensionless time factor (Table Time Factor) a is the radius of the cone Ir is the rigidity index t is the time at the degree of consolidation

Table Time Factor. T* versus degree of dissipation (Teh and Houlsby, 1991)

Degree of Dissipation (%)

20 30 40 50 60 70 80

T* (u2) 0.038 0.078 0.142 0.245 0.439 0.804 1.60

The coefficient of consolidation is typically analyzed using the time (t50) corresponding to a degree of dissipation of 50% (u50). In order to determine t50, dissipation tests must be taken to a pressure less than u50. The u50 value is half way between the initial maximum pore pressure and the equilibrium pore pressure value, known as u100. To estimate u50, both the initial maximum pore pressure and u100 must be known or estimated. Other degrees of dissipations may be considered, particularly for extremely long dissipations. At any specific degree of dissipation the equilibrium pore pressure (u at t100) must be estimated at the depth of interest. The equilibrium value may be determined from one or more sources such as measuring the value directly (u100), estimating it from other dissipations in the same profile, estimating the phreatic surface and assuming hydrostatic conditions, from nearby soundings, from client provided information, from site observations and/or past experience, or from other site instrumentation.


For calculations of ch (Teh and Houlsby, 1991), t50 values are estimated from the corresponding pore pressure dissipation curve and a rigidity index (Ir) is assumed. For curves having an initial dilatory response in which an initial rise in pore pressure occurs before reaching a peak, the relative time from the peak value is used in determining t50. In cases where the time to peak is excessive, t50 values are not calculated. Due to possible inherent uncertainties in estimating Ir, the equilibrium pore pressure and the effect of an initial dilatory response on calculating t50, other methods should be applied to confirm the results for ch. Additional published methods for estimating the coefficient of consolidation from a piezocone test are described in Burns and Mayne (1998, 2002), Jones and Van Zyl (1981), Robertson et al. (1992) and Sully et al. (1999). A summary of the pore pressure dissipation tests and dissipation plots are presented in the relevant appendix.

REFERENCES

ASTM D5778-12, 2012, "Standard Test Method for Performing Electronic Friction Cone and Piezocone Penetration Testing of Soils", ASTM, West Conshohocken, US. Burns, S.E. and Mayne, P.W., 1998, “Monotonic and dilatory pore pressure decay during piezocone tests”, Canadian Geotechnical Journal 26 (4): 1063-1073. Burns, S.E. and Mayne, P.W., 2002, “Analytical cavity expansion-critical state model cone dissipation in fine-grained soils”, Soils & Foundations, Vol. 42(2): 131-137. Jones, G.A. and Van Zyl, D.J.A., 1981, “The piezometer probe: a useful investigation tool”, Proceedings, 10th International Conference on Soil Mechanics and Foundation Engineering, Vol. 3, Stockholm: 489-495. Lunne, T., Robertson, P.K. and Powell, J. J. M., 1997, “Cone Penetration Testing in Geotechnical Practice”, Blackie Academic and Professional. Mayne, P.W., 2013, “Evaluating yield stress of soils from laboratory consolidation and in-situ cone penetration tests”, Sound Geotechnical Research to Practice (Holtz Volume) GSP 230, ASCE, Reston/VA: 406-420. Mayne, P.W., 2014, “Interpretation of geotechnical parameters from seismic piezocone tests”, CPT’14 Keynote Address, Las Vegas, NV, May 2014. Mayne, P.W. and Peuchen, J., 2012, “Unit weight trends with cone resistance in soft to firm clays”, Geotechnical and Geophysical Site Characterization 4, Vol. 1 (Proc. ISC-4, Pernambuco), CRC Press, London: 903-910. Robertson, P.K., 1990, “Soil Classification Using the Cone Penetration Test”, Canadian Geotechnical Journal, Volume 27: 151-158. Robertson, P.K., 2009, “Interpretation of cone penetration tests – a unified approach”, Canadian Geotechnical Journal, Volume 46: 1337-1355. Robertson, P.K., Campanella, R.G., Gillespie, D. and Greig, J., 1986, “Use of Piezometer Cone Data”, Proceedings of InSitu 86, ASCE Specialty Conference, Blacksburg, Virginia. Robertson, P.K., Sully, J.P., Woeller, D.J., Lunne, T., Powell, J.J.M. and Gillespie, D.G., 1992, “Estimating coefficient of consolidation from piezocone tests”, Canadian Geotechnical Journal, 29(4): 551-557. Sully, J.P., Robertson, P.K., Campanella, R.G. and Woeller, D.J., 1999, “An approach to evaluation of field CPTU dissipation data in overconsolidated fine-grained soils”, Canadian Geotechnical Journal, 36(2): 369-381. Teh, C.I., and Houlsby, G.T., 1991, “An analytical study of the cone penetration test in clay”, Geotechnique, 41(1): 17-34.

APPENDICES

The appendices listed below are included in the report:

Cone Penetration Test Summary and Standard Cone Penetration Test Plots

Advanced Cone Penetration Test Plots with Ic, Su(Nkt) and N1(60)

Pore Pressure Dissipation Summary and Pore Pressure Dissipation Plots

Cone Penetration Test Summary and

Standard Cone Penetration Test Plots

Job No: 16-56073

Client: Alan Kropp & Associates

Project: 2527 San Pablo

Start Date: 03-Oct-2016

End Date: 03-Oct-2016

CONE PENETRATION TEST SUMMARY

Sounding ID File Name Date Cone

Assumed Phreatic

Surface1

(ft)

Final

Depth

(ft)

Northing2

(m)

Easting

(m)

Refer to

Notation

Number

CPT-01 16-56073_CP01 03-Oct-2016 443:T1500F15U500 13.00 48.56 4190585 562529 3

CPT-02 16-56073_CP02 03-Oct-2016 443:T1500F15U500 13.00 51.84 4190566 562542 3

1. The assumed phreatic surface was based on pore pressure dissipation tests unless otherwise noted. Hydrostatic conditions were assumed for the calculated parameters.

2. Coordinates were collected with a consumer grade GPS device with datum WGS84/UTM Zone 10 North.

3. The assumed phreatic surface was based on an open hole water level measurement at CPT-01.

Sheet 1 of 1

The reported coordinates were acquired from consumer grade GPS equipment and are only approximate locations. The coordinates should not be used for design purposes.

0 200 400

0

10

20

30

40

50

60

qt (tsf)

De

pth

(fe

et)

0.0 5.0 10.0

fs (tsf)

0 5 10

Rf (%)

0 100 2000

u (ft)

0 6 12

SBT

Alan Kropp & AssociatesJob No: 16-56073

Date: 10:03:16 08:23

Site: Berkeley California

Sounding: CPT-01

Cone: 443:T1500F15U500

Max Depth: 14.800 m / 48.56 ftDepth Inc: 0.050 m / 0.164 ftAvg Int: Every Point

File: 16-56073_CP01.CORUnit Wt: SBT Zones

SBT: Robertson and Campanella, 1986Coords: UTM 10 N N: 4190585m E: 562529m Page No: 1 of 1

UndefinedSilt

Clay

Silty ClaySilty Clay

Clay

Silty ClayClay

Silty ClayClay

Silty Clay

Clayey SiltClay

Cemented SandSandy SiltCemented SandClayey SiltStiff Fine Grained

Stiff Fine GrainedCemented SandSilty Clay

Clayey Silt

Silt

Silty ClayClayey SiltSilty Clay

Stiff Fine Grained

Cemented Sand

Stiff Fine Grained

ClaySilty ClayStiff Fine GrainedStiff Fine GrainedSilty Sand/SandCemented Sand

Stiff Fine GrainedCemented SandSilty Clay

Silt

Clayey Silt

Cemented Sand

UndefinedSilty Sand/SandUndefined

Refusal Refusal Refusal Refusal

Equilibrium Pore Pressure (Ueq) Assumed Ueq Hydrostatic LineDissipation, Ueq not achievedDissipation, Ueq achieved

Drill Out Drill Out Drill Out Drill Out


0 200 400

0

10

20

30

40

50

60

qt (tsf)

De

pth

(fe

et)

0.0 5.0 10.0

fs (tsf)

0 5 10

Rf (%)

0 100 2000

u (ft)

0 6 12

SBT


Date: 10:03:16 09:53


Sounding: CPT-02

Cone: 443:T1500F15U500


File: 16-56073_CP02.CORUnit Wt: SBT Zones


UndefinedSandy SiltClayey SiltClayey SiltSiltSilty Clay

Silty Clay

Clayey Silt

Clayey Silt

Clay

Clay

Silty Clay

ClayClayClaySandy SiltCemented SandStiff Fine GrainedStiff Fine GrainedCemented SandSandy SiltSilty Clay

Silt

Clayey SiltSilty ClaySilty ClaySilty ClaySilty Clay

Silty Clay

Stiff Fine Grained

Clay

Clayey SiltClayStiff Fine GrainedClaySilty Clay

Stiff Fine Grained

Clay

Stiff Fine GrainedClay

Clayey Silt

Silty Clay

SiltClayey SiltSilty Clay

SiltClayey Silt

Stiff Fine GrainedClayey SiltStiff Fine Grained

Clayey SiltSiltUndefined

Target Depth Target Depth Target Depth Target Depth

Equilibrium Pore Pressure (Ueq) Assumed Ueq Hydrostatic LineDissipation, Ueq not achievedDissipation, Ueq achieved

Drill Out Drill Out Drill Out Drill Out

Advanced Cone Penetration Test Plots with Ic, Su(Nkt) and N1(60)


0 200 400

0

10

20

30

40

50

60

qt (tsf)

De

pth

(fe

et)

0 10 20

fs (tsf)

0 1 2 3 4

Ic

0 4 8

Su (Nkt) (tsf)

0 100 200

N1(60) (bpf)


Date: 10:03:16 08:23


Sounding: CPT-01

Cone: 443:T1500F15U500


File: 16-56073_CP01.CORUnit Wt: SBT ZonesSu Nkt: 15.0


Refusal Refusal Refusal Refusal Refusal

N(60) (bpf)

Drill Out Drill Out Drill Out Drill Out Drill Out


0 200 400

0

10

20

30

40

50

60

qt (tsf)

De

pth

(fe

et)

0 10 20

fs (tsf)

0 1 2 3 4

Ic

0 4 8

Su (Nkt) (tsf)

0 100 200

N1(60) (bpf)


Date: 10:03:16 09:53


Sounding: CPT-02

Cone: 443:T1500F15U500


File: 16-56073_CP02.CORUnit Wt: SBT ZonesSu Nkt: 15.0


Target Depth Target Depth Target Depth Target Depth Target Depth

N(60) (bpf)

Drill Out Drill Out Drill Out Drill Out Drill Out

Pore Pressure Dissipation Summary and

Pore Pressure Dissipation Plots

Job No: 16-56073

Client: Alan Kropp & Associates

Project: 2527 San Pablo

Start Date: 03-Oct-2016

End Date: 03-Oct-2016

CPTu PORE PRESSURE DISSIPATION SUMMARY

Sounding ID File NameCone Area

(cm2)

Duration

(s)

Test

Depth

(ft)

Estimated

Equilibrium Pore

Pressure Ueq

(psi)

Calculated

Phreatic

Surface

(ft)

CPT-01 16-56073_CP01 15 300 37.89 Not Achieved





Sheet 1 of 1

0 100 200 300 400

0.0

20.0

40.0

0.0

-20.0

-40.0

Time (s)

Pore

Pre

ssure

(ft

)Alan Kropp & Associates

Job No: 16-56073

Date: 10/03/2016 08:23


Sounding: CPT-01

Cone: 443:T1500F15U500

Cone Area: 15 sq cm

Trace Summary:

Filename: 16-56073_CP01.PPF

Depth: 11.550 m / 37.893 ft

Duration: 300.0 s

U Min: -14.1 ft

U Max: 24.9 ft

0 40 80 120 160

0.0

5.0

10.0

0.0

-5.0

-10.0

Time (s)

Pore

Pre

ssure

(ft


Job No: 16-56073

Date: 10/03/2016 08:23


Sounding: CPT-01

Cone: 443:T1500F15U500

Cone Area: 15 sq cm

Trace Summary:


Depth: 13.850 m / 45.439 ft

Duration: 120.0 s

U Min: -4.8 ft

U Max: -1.5 ft

0 60 120 180 240

0.0

5.0

10.0

0.0

-5.0

-10.0

Time (s)

Pore

Pre

ssure

(ft


Job No: 16-56073

Date: 10/03/2016 08:23


Sounding: CPT-01

Cone: 443:T1500F15U500

Cone Area: 15 sq cm

Trace Summary:


Depth: 14.400 m / 47.244 ft

Duration: 200.0 s

U Min: -1.1 ft

U Max: 7.2 ft

0 50 100 150 200

0.0

40.0

80.0

0.0

-40.0

-80.0

Time (s)

Pore

Pre

ssure

(ft


Job No: 16-56073

Date: 10/03/2016 09:53


Sounding: CPT-02

Cone: 443:T1500F15U500

Cone Area: 15 sq cm

Trace Summary:


Depth: 4.400 m / 14.436 ft

Duration: 140.0 s

U Min: -16.6 ft

U Max: 55.9 ft

0 120 240 360 480

0.0

30.0

60.0

90.0

0.0

-30.0

Time (s)

Pore

Pre

ssure

(ft


Job No: 16-56073

Date: 10/03/2016 09:53


Sounding: CPT-02

Cone: 443:T1500F15U500

Cone Area: 15 sq cm

Trace Summary:


Depth: 8.800 m / 28.871 ft

Duration: 430.0 s

U Min: -12.5 ft

U Max: 69.6 ft

APPENDIX B BORING LOGS BY STELLAR ENVIRONMENTAL SOLUTIONS, INC.

Soil Boring Log

PROJECTLOCATIONTOTAL DEPTHSURFACE ELEV.DRILLING COMPANYDRILLER GEOLOGIST DATE DRILLED

OWNERPROJECT NUMBERBOREHOLE DIA.WATER FIRST ENCOUNTEREDDRILLING METHOD

BORING NUMBER Page of

DEPTH(feet)

GRAPHICLOG DESCRIPTION/SOIL CLASSIFICATION REMARKS

0

2

4

6

8

10

12

14

16

18

20

2016

-04-

03

Rolinsky

2527 San Pablo Ave.

16 feet bgs

--

Cascade

Arturo

B1 1 1

Babitt

2016-04

2.25 inch

8 ft.

Direct Push S. Bittman 1/22/16

2" asphaltCL-SC, silty clay to sandy clay, dark brown, damp, stiff

SP-SC, sand to clayey sand, dark grey, loose, wet

CL, silty clay, grey brown, damp to moist, stiff

CL, gravelly clay, greenish brown, damp, stiff

Total drilled depth = 16 ft.

Discrete soil sample=

B1-3

B1-6

B1-10

B1-10B1-14

First encountered groundwater Equilibrated groundwater level

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

04

Rolinsky

2527 San Pablo Ave.

12 feet bgs

--

Cascade

Arturo

B2 1 1

Babitt

2016-04

2.25 inch

N/A


2" asphaltCL, silty clay, dark brown, damp, stiff

Color change to brown @ 6 ft.


Collect composite sample B2-comp from 4', 8' and 12'


Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

05

Rolinsky

2527 San Pablo Ave.

12 feet bgs

--

Cascade

Arturo

B3 1 1

Babitt

2016-04

2.25 inch

N/A


2" asphaltCL, silty clay, dark brown, damp, stiff



Collect composite sample B3-comp from 4', 8' and 12'


Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

06

Rolinsky

2527 San Pablo Ave.

4 feet bgs

--

Cascade

Arturo

B4 1 1

Babitt

2016-04

2.25 inch

N/A


2" concrete

CL, silty clay, dark brown, damp, stiff

Baserock



B4-3Discrete soil sample

=B4-3

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

07

Rolinsky

2527 San Pablo Ave.

5 feet bgs

--

Cascade

Arturo

B5 1 1

Babitt

2016-04

2.25 inch

N/A


2" concrete

CL, silty clay, dark brown, damp, very stiff

Baserock



B5-3Discrete soil sample

Set soil gas probe @ 5 ft. for sample SG-1

=B5-3

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

08

Rolinsky

2527 San Pablo Ave.

8 feet bgs

--

Cascade

Arturo

B6 1 1

Babitt

2016-04

2.25 inch

N/A


2" concrete shop floor

CL, silty clay, dark brown, damp, stiff


2" sand



B6-4 Discrete soil sample=B6-4

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

09

Rolinsky

2527 San Pablo Ave.

12 feet bgs

--

Cascade

Arturo

B7 1 1

Babitt

2016-04

2.25 inch

N/A


2" asphalt

CL, silty clay, dark brown to black, moist, soft, hydrocarbon odor @ 3-5'

CL, gravelly clay, brown, damp, soft

2" baserock

SP, dark grey, damp, fine grained, loose

CL, silty clay, greenish grey, damp, stiff, slight hydrocarbon odor 10-12'



B7-4

B7-11.5

B7-11.5Discrete soil sample

=

DEPTH(feet)

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

10

Rolinsky

2527 San Pablo Ave.

18 feet bgs

--

Cascade

Arturo

B8 1 1

Babitt

2016-04

2.25 inch

12 ft.


2" asphalt

Sandy clay fill, brown, damp, no discoloration or odor

CL, silty clay, brown, damp, stiff, no odor

Color change to grey @ 9 ft.

SP, sand, dark brown, fine grained, wet, no odor

CL, silty clay, brown, damp, stiff, no odor, gravelly @ 14 ft.

Set temporary well screen 8'-18' for collection of sample B8-W

GC, clayey gravel, brown, damp, no odor



B8-13

B8-13


DEPTH(feet)

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

11

Rolinsky

2527 San Pablo Ave.

24 feet bgs

--

Cascade

Arturo

B9 1 2

Babitt

2016-04

2.25 inch

16 ft.


2" asphalt

CL, silty clay, medium brown, damp, stiff

Becomes green with hydrocarbon odor @ 8 ft.

GC, clayey gravel, brown, wet, dense Set temporary well screen 14'-24' for collection of sample B9-W


B9-10B9-10

B9-19


DEPTH(feet)

4" baserock

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

13

Rolinsky

2527 San Pablo Ave.

12 feet bgs

--

Cascade

Arturo

B10 1 1

Babitt

2016-04

2.25 inch

N/A


2" concrete shop floor

Gravel fill from hydraulic hoist removal

CL, silty clay, brown, damp, stiff, no discoloration or odor


B10-8B10-8


DEPTH(feet)


Soil Boring Log




DEPTH(feet)


20

22

24

2016

-04-

12

Rolinsky

2527 San Pablo Ave.

24 feet bgs

--

Cascade

Arturo

B9 2 2

Babitt

2016-04

2.25 inch

16 ft.



Clayey gravel, brown, wet

CL, gravelly clay, brown, damp, stiff, 10% gravel to 1/8"


DEPTH(feet)

Soil Boring Log




DEPTH(feet)


0

2

4

6

8

10

12

14

16

18

20

2016

-04-

14

Rolinsky

2527 San Pablo Ave.

5 feet bgs

--

Cascade

Arturo

B11 1 1

Babitt

2016-04

2.25 inch

N/A


2" asphalt

CL-SC, silty clay to clayey sand, brown & grey, damp, stiff, fill


DEPTH(feet)

Total drilled depth = 5 ft.Set soil vapor probe @ 5' for sample SG-2

APPENDIX C LIQUEFACTION ANALYSIS REPORT

L I Q U E F A C T I O N A N A L Y S I S R E P O R T

Input parameters and analysis dataAnalysis method:Fines correction method:Points to test:Earthquake magnitude Mw:Peak ground acceleration:

NCEER (1998)NCEER (1998)Based on Ic value7.100.76

G.W.T. (in-situ):G.W.T. (earthq.):Average results interval:Ic cut-off value:Unit weight calculation:

Project title : 2527 SAN PABLO AVENUE Location : Berkeley, California

ALAN KROPP & ASSOCIATESGeotechnical Consultants2140 Shattuck Avenue, Berkeley, Californiawww.akropp.com

CPT file : CPT-1

5.00 ft5.00 ft12.60Based on SBT

Use fill:Fill height:Fill weight:Trans. detect. applied:Kσ applied:

NoN/AN/AYesYes

Clay like behaviorapplied:Limit depth applied:Limit depth:MSF method:

Sands onlyNoN/AMethod based

Cone resistance

qt (tsf)4002000

Dept

h (f

t)

484644424038363432302826242220181614121086420

Cone resistance SBTn Plot

Ic (Robertson 1990)4321

48464442403836343230282624222018161412108642

SBTn Plot CRR plot

CRR & CSR0.60.40.20

484644424038363432302826242220181614121086420

CRR plot

During earthq.

Qtn,cs200180160140120100806040200

Cycl

ic S

tres

s Ra

tio*

(CSR

*)

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Liquefaction

No Liquefaction

Normalized friction ratio (%)0.1 1 10

Norm

aliz

ed C

PT p

enet

ratio

n re

sista

nce

1

10

100

1,000

Friction Ratio

Rf (%)1086420

48464442403836343230282624222018161412108642

Friction Ratio

Mw=71/2, sigma'=1 atm base curve Summary of liquefaction potential

FS Plot

Factor of safety21.510.50

484644424038363432302826242220181614121086420

FS Plot

During earthq.

Zone A1: Cyclic liquefaction likely depending on size and duration of cyclic loadingZone A2: Cyclic liquefaction and strength loss likely depending on loading and groundgeometryZone B: Liquefaction and post-earthquake strength loss unlikely, check cyclic softeningZone C: Cyclic liquefaction and strength loss possible depending on soil plasticity,brittleness/sensitivity, strain to peak undrained strength and ground geometry

CLiq v.2.0.6.82 - CPT Liquefaction Assessment Software - Report created on: 10/12/2016, 3:38:53 PMProject file: H:\OpenJobs\2800s\2814-1A 2527 San Pablo Avenue Building\Liquefaction Analysis\2814-1A 2527 San Pablo Avenue Liquefaction Result.clq

1

This software is licensed to: Alan Kropp and Associates CPT name: CPT-1

Cone resistance

qt (tsf)4003002001000

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Cone resistance

C P T b a s i c i n t e r p r e t a t i o n p l o t sFriction Ratio

Rf (%)1086420

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

Friction Ratio Pore pressure

u (psi)150100500

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Pore pressure

Insitu

SBT Plot

Ic(SBT)4321

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBT Plot Soil Behaviour Type

SBT (Robertson et al. 1986)181614121086420

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Soil Behaviour Type

Sensitive f ine grainedClay & silty clay

Clay

Clay & silty clay

Clay

Clay & silty clay

Clay

Clay & silty clayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilClayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soil

Clay & silty clay

Silty sand & sandy siltClayClayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilClay & silty clayClay & silty clayClayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilClay & silty clayClay & silty clayVery dense/stif f soilVery dense/stif f soilClay & silty clayVery dense/stif f soil

CLiq v.2.0.6.82 - CPT Liquefaction Assessment Software - Report created on: 10/12/2016, 3:38:53 PM 2Project file: H:\OpenJobs\2800s\2814-1A 2527 San Pablo Avenue Building\Liquefaction Analysis\2814-1A 2527 San Pablo Avenue Liquefaction Result.clq

Input parameters and analysis dataAnalysis method:Fines correction method:Points to test:Earthquake magnitude Mw:Peak ground acceleration:Depth to water table (insitu):

NCEER (1998)NCEER (1998)Based on Ic value7.100.765.00 ft

Depth to water table (erthq.):Average results interval:Ic cut-off value:Unit weight calculation:Use fill:Fill height:

5.00 ft12.60Based on SBTNoN/A

Fill weight:Transition detect. applied:Kσ applied:Clay like behavior applied:Limit depth applied:Limit depth:

N/AYesYesSands onlyNoN/A

SBT legend1. Sensitive fine grained2. Organic material3. Clay to silty clay

4. Clayey silt to silty5. Silty sand to sandy silt6. Clean sand to silty sand

7. Gravely sand to sand8. Very stiff sand to9. Very stiff fine grained


Norm. cone resistance

Qtn200150100500

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. cone resistance

C P T b a s i c i n t e r p r e t a t i o n p l o t s ( n o r m a l i z e d )Norm. friction ratio

Fr (%)1086420

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. friction ratio Nom. pore pressure ratio

Bq10.80.60.40.20-0.2

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Nom. pore pressure ratio SBTn Plot


Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Plot Norm. Soil Behaviour Type

SBTn (Robertson 1990)181614121086420

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. Soil Behaviour Type

Sand & silty sandVery dense/stif f soilVery dense/stif f soil

Clay & silty clayVery dense/stif f soilClayClay & silty clayClay

Clay & silty clay

Very dense/stif f soilVery dense/stif f soilVery dense/stif f soilClayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soil

Clay & silty clay

ClayClay & silty clayClayClayVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilClayClayClayVery dense/stif f soil

Very dense/stif f soil

Very dense/stif f soilClay

Clay & silty clayClayVery dense/stif f soilClay & silty clay


SBTn legend1. Sensitive fine grained2. Organic material3. Clay to silty clay










Total cone resistance

qt (tsf)4003002001000

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Total cone resistance

L i q u e f a c t i o n a n a l y s i s o v e r a l l p l o t s ( i n t e r m e d i a t e r e s u l t s )SBTn Index


Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Index Norm. cone resistance

Qtn200150100500

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. cone resistance Grain char. factor

Kc109876543210

Dept

h (ft

)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Grain char. factor Corrected norm. cone resistance

Qtn,cs200150100500

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Corrected norm. cone resistance









Cone resistance

qt (tsf)4003002001000

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Cone resistance SBTn Plot


Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Plot FS Plot


Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0FS Plot

During earthq.

Vertical settlements

Settlement (in)0.80.60.40.20

Dept

h (f

t)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Vertical settlements

E s t i m a t i o n o f p o s t - e a r t h q u a k e s e t t l e m e n t s

Strain plot

Volumentric strain (%)6543210

Dept

h (ft

)

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Strain plot


Abbreviationsqt:Ic:FS:Volumentric strain:

Total cone resistance (cone resistance qc corrected for pore water effects)Soil Behaviour Type IndexCalculated Factor of Safety against liquefactionPost-liquefaction volumentric strain

L I Q U E F A C T I O N A N A L Y S I S R E P O R T

Input parameters and analysis dataAnalysis method:Fines correction method:Points to test:Earthquake magnitude Mw:Peak ground acceleration:

NCEER (1998)NCEER (1998)Based on Ic value7.100.76

G.W.T. (in-situ):G.W.T. (earthq.):Average results interval:Ic cut-off value:Unit weight calculation:

Project title : 2527 SAN PABLO AVENUE Location : Berkeley, California

ALAN KROPP & ASSOCIATESGeotechnical Consultants2140 Shattuck Avenue, Berkeley, Californiawww.akropp.com

CPT file : CPT-02

5.00 ft5.00 ft12.60Based on SBT

Use fill:Fill height:Fill weight:Trans. detect. applied:Kσ applied:

NoN/AN/ANoYes

Clay like behaviorapplied:Limit depth applied:Limit depth:MSF method:

Sands onlyNoN/AMethod based

Cone resistance

qt (tsf)2001000

Dept

h (f

t)

5250484644424038363432302826242220181614121086420

Cone resistance SBTn Plot


5048464442403836343230282624222018161412108642

SBTn Plot CRR plot

CRR & CSR0.60.40.20

5250484644424038363432302826242220181614121086420

CRR plot

During earthq.

Qtn,cs200180160140120100806040200

Cycl

ic S

tres

s Ra

tio*

(CSR

*)

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Liquefaction

No Liquefaction

Normalized friction ratio (%)0.1 1 10

Norm

aliz

ed C

PT p

enet

ratio

n re

sista

nce

1

10

100

1,000

Friction Ratio

Rf (%)1086420

5048464442403836343230282624222018161412108642

Friction Ratio

Mw=71/2, sigma'=1 atm base curve Summary of liquefaction potential

FS Plot


5250484644424038363432302826242220181614121086420

FS Plot

During earthq.

Zone A1: Cyclic liquefaction likely depending on size and duration of cyclic loadingZone A2: Cyclic liquefaction and strength loss likely depending on loading and groundgeometryZone B: Liquefaction and post-earthquake strength loss unlikely, check cyclic softeningZone C: Cyclic liquefaction and strength loss possible depending on soil plasticity,brittleness/sensitivity, strain to peak undrained strength and ground geometry

CLiq v.2.0.6.82 - CPT Liquefaction Assessment Software - Report created on: 10/12/2016, 3:40:13 PMProject file: H:\OpenJobs\2800s\2814-1A 2527 San Pablo Avenue Building\Liquefaction Analysis\2814-1A 2527 San Pablo Avenue Liquefaction Result.clq

1


Cone resistance

qt (tsf)2001000

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Cone resistance

C P T b a s i c i n t e r p r e t a t i o n p l o t sFriction Ratio

Rf (%)1086420

Dept

h (f

t)

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

Friction Ratio Pore pressure

u (psi)4002000

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Pore pressure

Insitu

SBT Plot

Ic(SBT)4321

Dept

h (f

t)

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBT Plot Soil Behaviour Type

SBT (Robertson et al. 1986)181614121086420

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Soil Behaviour Type

Sensitive f ine grained

Clay & silty clayClay & silty clayClay & silty clay

Clay & silty clay

ClayClay & silty clay

ClaySilty sand & sandy siltSand & silty sandVery dense/stif f soilVery dense/stif f soilVery dense/stif f soilSilty sand & sandy silt

Clay & silty clay

Clay

Very dense/stif f soilClay & silty clayClayClay & silty clayClay

Clay

Very dense/stif f soilClay & silty clayVery dense/stif f soil

Clay & silty clay

Very dense/stif f soilSilty sand & sandy siltVery dense/stif f soil

Very dense/stif f soil

Silty sand & sandy silt







N/ANoYesSands onlyNoN/A

SBT legend1. Sensitive fine grained2. Organic material3. Clay to silty clay




Norm. cone resistance

Qtn200150100500

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. cone resistance

C P T b a s i c i n t e r p r e t a t i o n p l o t s ( n o r m a l i z e d )Norm. friction ratio

Fr (%)1086420

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. friction ratio Nom. pore pressure ratio

Bq10.80.60.40.20-0.2

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Nom. pore pressure ratio SBTn Plot


Dept

h (f

t)

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Plot Norm. Soil Behaviour Type

SBTn (Robertson 1990)181614121086420

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. Soil Behaviour Type

Sand & silty sandClay & silty clay

Clay & silty clay

Silty sand & sandy siltClay

Clay & silty clay

ClayVery dense/stif f soilVery dense/stif f soil

Very dense/stif f soilVery dense/stif f soilSand & silty sandSilty sand & sandy silt

Clay & silty clay

Very dense/stif f soilClay & silty clayVery dense/stif f soilClay & silty clayClayClay & silty clayClayClay & silty clayClay & silty clay

Very dense/stif f soilClay & silty clayVery dense/stif f soil

Clay & silty clayClay

Clay & silty clayClay

Clay & silty claySilty sand & sandy siltClayClay & silty clay

Clay & silty clay


SBTn legend1. Sensitive fine grained2. Organic material3. Clay to silty clay










Total cone resistance

qt (tsf)250200150100500

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Total cone resistance

L i q u e f a c t i o n a n a l y s i s o v e r a l l p l o t s ( i n t e r m e d i a t e r e s u l t s )SBTn Index


Dept

h (f

t)

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Index Norm. cone resistance

Qtn200150100500

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Norm. cone resistance Grain char. factor

Kc109876543210

Dept

h (ft

)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Grain char. factor Corrected norm. cone resistance

Qtn,cs200150100500

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Corrected norm. cone resistance









Cone resistance

qt (tsf)250200150100500

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Cone resistance SBTn Plot


Dept

h (f

t)

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

SBTn Plot FS Plot


Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0FS Plot

During earthq.

Vertical settlements

Settlement (in)1.510.50

Dept

h (f

t)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Vertical settlements

E s t i m a t i o n o f p o s t - e a r t h q u a k e s e t t l e m e n t s

Strain plot

Volumentric strain (%)6543210

Dept

h (ft

)

52

50

48

46

44

42

40

38

36

34

32

30

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0Strain plot


Abbreviationsqt:Ic:FS:Volumentric strain:

Total cone resistance (cone resistance qc corrected for pore water effects)Soil Behaviour Type IndexCalculated Factor of Safety against liquefactionPost-liquefaction volumentric strain

a n k r - berkeley, california · 10/21/2016 · (sbt), which is interpreted by the cpt software...

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