The Department of Veterans Affairs (VA) is proposing to construct three new buildings and perform chiller system upgrades at the existing medical center campus in Long Beach, California. As part of the pre-design process, Geosyntec was selected to perform a geotechnical investigation and seismic study. The geotechnical investigation was performed to characterize the subsurface at the site, perform engineering analyses, and provide geotechnical engineering recommendations related to design and construction of the proposed facilities. The investigation included a seismic study performed to evaluate the seismic hazard at the site and develop site-specific ground motion parameters in accordance with the VA Seismic Design Requirements, H-18-8.
Geosyntec's Scope of Services
For this project, Geosyntec performed a site reconnaissance and field exploration program, geotechnical laboratory testing, and geologic and engineering evaluations and analyses, and prepared a report documenting the results of our investigation. The field exploration program consisted of borings advanced using hollow-stem auger drilling techniques and cone penetration test (CPT) soundings. One CPT included seismic testing to measure shear wave velocity at regular intervals along the subsurface sounding. Geotechnical laboratory testing was performed to characterize the subsurface soils encountered. Engineering analysis was performed to provide recommendations for site earthwork and grading, shallow foundations, permanent and temporary retaining walls, flexible and rigid pavements, and corrosion potential.
As part of the geotechnical investigation, Geosyntec performed a geologic and seismic hazards analysis of the site. The geologic hazards analysis included evaluation of the potential for fault rupture, soil liquefaction, and flooding. The seismic hazard evaluation included site-specific probabilistic seismic hazard analysis in accordance with the ASCE 7-10 requirements.
The field investigation was performed within an active medical center without interruption to site operations. Site-specific probabilistic seismic hazard analysis with Next Generation Attenuation (NGA) relationships allowed for more economical seismic design of proposed facilities.