Veterans' Memorial Auditorium Seismic Evaluation

San Rafael, California, USA

Slate performed a geotechnical investigation and seismic evaluation of the Marin Veterans’ Memorial Auditorium (VMA). Our work supported a seismic evaluation and retrofit design by Wiss, Janney, Elstner Associates of this unique 34,000 square-foot, circular building with an attached rectangular “arm.”

An iconic and landmark building in the Marin area, the auditorium was designed by Taliesin Associated Architects, a successor firm of Frank Lloyd Wright. The auditorium seats 2,000 and hosts a variety of events from the Marin Symphony to corporate meetings. Located near multiple faults, the VMA posed a seismic safety risk to the community; it would have likely experienced significant shaking and moderate to high liquefaction during a major earthquake.

Our services included a limited geotechnical investigation, development of ground motions, assessment of the potential for earthquake-induced geohazards, and geotechnical and geologic recommendations for the seismic evaluation and proposed retrofit of the VMA. We collected data from previous geotechnical investigations done by other companies in the vicinity of the VMA. Slate performed a site-specific probabilistic seismic hazard analysis (PSHA), a deterministic seismic hazard analysis (DSHA), and non-linear site response analysis. We also provided a recommendation for foundation-level response spectra, evaluated earthquake-induced hazards, and estimated lateral earth pressures on existing grade beams and basement walls.

Technical components:

  • Geotechnical investigation and seismic evaluation
  • Foundation: grade beams and deep foundation elements
  • Soils: man-made fill, Young Bay Mud (YBM) with peat, alluvium, and weathered sandstone and shale bedrock
  • Likelihood of significant shaking during a major earthquake
  • Moderate to high risk of liquefaction on the site due to shallow sand and gravel
Marin VMA