Civil and Environmental Engineering Department Seminar: Seismic Performance Evaluation and Retrofit of Vulnerable Concentrically Braced Frames

Seminar | February 7 | 10-11 a.m. | 542 Davis Hall

 Andrew Sen

 Civil and Environmental Engineering (CEE)

Concentrically braced frames built prior to the codification of capacity-based and other ductile design provisions constitute a substantial proportion of steel building infrastructure on the West Coast of the US. These buildings, built prior to about 1990, utilize a wide variety of connection and system configurations with deficiencies expected to lead to significant damage and potentially collapse in moderate-to-large earthquakes. Vulnerable concentrically braced frames will likely require seismic retrofit to ensure occupant safety and mitigate economic loss, especially in view of a growing resiliency ethic in communities exposed to high seismic risk.

This seminar will describe the state of existing concentrically braced frame infrastructure and the development of a cost-effective seismic retrofit methodology that leverages yielding mechanisms and suppresses severe failure modes inherent to the original structure. These timely contributions to structural engineering practice are based upon a comprehensive experimental and computational research program that builds from subassemblage testing to probabilistically evaluate the seismic performance of existing and retrofitted systems using nonlinear response-history analysis. Research outcomes and plans for future work will be discussed in the context of advancing the role of earthquake engineering within broader resiliency goals.

 leorig@berkeley.edu, 510-642-1762