The impact of a PEER funded research project “Stochastic Modeling and Simulation of Near-Fault Ground Motions for use in PBEE” is highlighted below. The project Principal Investigator is Armen Der Kiureghian, President, American University of Armenia; Taisei Professor of Civil Engineering Emeritus, UC Berkeley. The co-Principal Investigator is Mayssa Dabaghi, Assistant Professor, Department of Civil and Environmental Engineering, American University of Beirut, Lebanon. The research team includes Yara Daoud, Graduate Research Assistant, American University of Beirut, Lebanon.
This project contributes to the first step of PEER’s performance based earthquake engineering (PBEE) methodology, namely, characterization of the seismic hazard at a location of interest with a special focus on near-fault sites. Near-fault ground motions may possess distinct characteristics, including the rupture directivity effect that should be taken into account in the seismic risk and performance assessment of structures located nearby active faults.
Probabilistic seismic hazard analysis (PSHA) can be conducted by combining the proposed ground motion model and simulation procedure to seismic source characterization. This first step of PBEE is crucial for the ensuing steps of computing structural responses for the given hazard, defining and computing relevant measures of damage to structural and non-structural components and equipment, and computing decision variables that relate to casualties, cost, and downtime. These decision variables drive performance-based design of structures, rendering careful characterization of ground motions essential. Thus, we believe the results of this project will fill an important gap in the practice of PBEE.
By improving the existing near-fault ground motion model and simulation procedure, the research being conducted will facilitate the use of simulated ground motions in PBEE. Specifically, for any set of earthquake source and site characteristics, one can generate realistic simulated near-fault ground motions which have similar statistical characteristics as recorded motions in the NGA West2 database. These simulated motions can be used in response history analysis and in PBEE applications, in place of or in addition to recorded ground motions, without any need for scaling which is a questionable practice in many instances. For example, the outcome of this research can be used to characterize the level of ground shaking in the seismic performance assessment or design of long-period structures, such as tall buildings and long-span bridges in near-fault regions.