Hazard Mitigation

Liquefaction

 

Downer Elementary School - San Pablo, CA

Geotechnical and Geologic Hazards Investigation (2005)
Construction Observation and Testing Services (ongoing)

AKA conducted a design-level geotechnical investigation and geologic hazards study for the new Downer Elementary School campus in San Pablo, Contra Costa County. Downer is located in an alluvial plain underlain by soils that are susceptible to earthquake-induced liquefaction. Our study included drilling borings and performing cone penetration tests to evaluate geotechnical conditions, and producing a design-level geotechnical and geologic hazard evaluation report. The project includes ground improvement to mitigate liquefaction settlement to within allowable limits set by the project Structural Engineer. Our report was favorably peer-reviewed with no exceptions by the California Geological Survey.

AKA developed design-build specifications for ground improvement using stone columns and is currently providing comprehensive geotechnical engineering services during the construction of the new campus. The scope of our construction-phase services includes observation/testing during stone column installation, fill placement, and foundation construction; consultation; and preparation of daily reports, summary reports, and Geotechnical Verified Reports for submittal to the DSA.

Downer Elementary School  San Pablo, CA New CampusDowner Elementary School  San Pablo, CA New Campus

ODC Theater - San Francisco, CA

Geotechnical Investigation (2007)

AKA conducted a geotechnical investigation to seismically upgrade and renovate the existing ODC Theatre facility at 17th and Shotwell Streets in San Francisco, California. The purpose of the investigation was to conduct site-specific subsurface exploration to evaluate liquefaction and provide geotechnical recommendations for the design of the project. Because the site is within an official State Hazard Zone for liquefaction, the investigation conformed to the State Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication (SP) 117. The upper 28 feet of soils encountered in our investigation generally consisted of loose to medium-dense, potentially liquefiable, clean sands. We calculated that about 12.5 inches of total dynamic, compressional settlement could occur within the potentially liquefiable soil layers as a result of a large seismic event. We recommended improving the upper 35 feet of soil by compaction grouting and supporting the buildings on a concrete mat foundation.

ODC Theater

Berkeley Animal Shelter - Berkeley, CA

Geotechnical Investigation (2008)

AKA recently completed the geotechnical investigation for the new City of Berkeley Animal Shelter in West Berkeley, California. The proposed animal shelter site is located adjacent to the northern tip of Aquatic Park Lake in an area that was reclaimed from San Francisco Bay. Site characterization borings by AKA revealed an underlying soil profile of poorly compacted fill overlying soft and compressible Bay Deposits. Settlement of the fill and Bay Deposits under new site loads, liquefaction, and lateral spreading were the primary geotechnical site design issues. Several site development and foundation alternatives were considered to mitigate the significant geotechnical challenges of the site. Through an interactive design discussion with City of Berkeleys Department of Public Works and the project structural design consultant it was decided that a development scheme involving ground improvement with support of the building on a mat slab foundation was the preferred alterative for the project. Geotechnical recommendations were given by AKA for ground improvement utilizing Rammed Aggregate Piers.

Berkeley Animal ShelterBerkeley Animal Shelter

Alan Kropp & Associates, Inc. 2140 Shattuck Avenue Berkeley, CA 94704 Phone: (510) 841 5095 Fax: (510) 841 8357