An Overview of PEER’s Performance-Based Earthquake Engineering Methodology

Various analytical approaches to performance-based earthquake engineering are in development. This paper summarizes the approach being pursued by the Pacific Earthquake Engineering Research (PEER) Center. It works in four stages: hazard analysis, structural analysis, damage analysis, and loss analysis. In the hazard analysis, one evaluates the seismic hazard at the facility site, producing sample ground-motion time histories whose intensity measure (IM) is appropriate to varying hazard levels. In the structural-analysis phase, a nonlinear time-history structural analysis is performed to calculate the response of the facility to a ground motion of given IM in terms of drifts, accelerations, ground failure, or other engineering demand parameters (EDP). In the third, damage-analysis, phase, these EDPs are used with component fragility functions to determine measures of damage (DM) to the facility components. Finally, given DM, one evaluates repair efforts to determine repair costs, operability, and repair duration, and the potential for casualties. These measures of performance are referred to as decision variables (DV), since they can be used to inform stakeholder decisions about future performance. Each relationship, from location and design to IM, IM to EDP, EDP to DM, and DM to DV, involves uncertainty and is treated probabilistically. PEER is currently exercising and illustrating its methodology on six real facilities, called testbeds, each of which explores a different aspect of PBEE.