John Muir Health Ambulatory Care Center Seismic Retrofit

Walnut Creek | California

The 144,000 gross square feet building was originally constructed in 1984.  It consists of three stories of office space over a subterranean basement with space for primary care physicians, specialists, an Urgent Care Center, patient education, laboratory and imaging services.  ZFA was selected as the seismic retrofit specialist, and evaluated the existing building using the latest industry documents including ASCE 41. 

An initial evaluation indicated that significant strengthening may be required.  Subsequently, a more detailed and advanced nonlinear analysis of the existing structure identified that the core lateral force-resisting system was adequate, but selective components were deficient.  ZFA was able to communicate the key deficiencies to John Muir Health, and recommend a less intrusive and more cost effective retrofit program at selective locations.  Key deficiency retrofits were primarily limited to the basement and roof, and the need for new full height structural elements was eliminated.  This allowed for all of the retrofit work to be completed prior to the tenant improvement work, and improved the schedule and construction cost by eliminating conflict between the two phases.