The Existing Buildings Committee (EBC) is currently developing an annual seismic hazard reduction report card for municipalities throughout California. The initial effort will focus on a single major city in each SEAOC defined region of California: Los Angeles, San Diego, San Francisco, and Sacramento. The “report card” provides a letter grade (A through D) for the city’s effort to mitigate known seismic hazards associated with existing building stock. The four target building types comprise: unreinforced masonry, tilt-up concrete wall panel/masonry wall with flexible diaphragm, non-ductile concrete frames, and weak story buildings. The concept is to assign a simple grade (A, B, C, …) for the city’s work toward reducing the seismic risk attributable to each of these building types within their jurisdiction. The grades will be assigned considering a diverse set of factors: seismicity, percentage of building stock attributed to a specific building type, population at risk, long term plans to mitigate seismic risk and scope/efficacy of current seismic risk mitigation ordinances or programs. Through this effort, SEAOC hopes to engage the public, the eventual beneficiaries of such an effort. SEAOC has had a long standing role in representing the in the identification and mitigation of seismic risks posed by existing building stock. If a grading system can garner appropriate attention, we believe public support for mitigation ordinances or programs may result. With public support, we may motivate government leaders to develop an appetite for mitigating seismic risk.
We believe our effort is timely considering recent media interest in the safety of concrete buildings: (Link to LA Times study: http://www.latimes.com/local/la-me-earthquake-concrete-20131013-dto,0,15...) and the recently adopted soft/weak story ordinance in San Francisco.
The committee is currently working on metrics to establish grade assignments for each building type. Representatives from SEAOSC are leading the efforts for non-ductile concrete, SEAOSD representatives are leading the efforts for URM, SEAONC is leading the weak-story effort and SEAOCC is developing metrics for tilt-up concrete wall panel/masonry wall buildings. Each regional group will bring their progress to the SEAOC Existing Buildings Committee and ultimately the SEAOC Structural Standards Committee. After each grading format is set the committee plans to request a meeting with targeted building officials to confirm our data and discuss our program prior to releasing any information outside of SEAOC. The SEAOC EBC intends to maintain the program on an annual basis, with first grades released at the SEAOC Annual convention in September 2014. Any interested SEAOC members should contact the local Existing Building Code Committee chair.
Michael T. Braund, S.E., SEAOC Existing Buildings Committee, Chair 2012-13
Kevin S. Moore, S.E., SEAOC Structural Standards Committee, Chair