Fuzzy optimization for ground motion intensity measures to characterize the response of the pile-supported wharf in liquefiable soils

Abstract

In the Performance-Based Earthquake Engineering (PBEE) framework of Pacific Earthquake Engineering Research (PEER) Center, the structural seismic responses are usually expressed by probabilistic seismic demand models (PSDMs), which provide a representative relation between ground motion intensity measures (IMs) and engineering demand parameters (EDPs). Since the degree of uncertainty of PSDMs is dependent on the IMs used, the selection of optimal IM is very beneficial to enhance the credibility and ultimately contributes to a reliable decision. PSDMs and the fuzzy comprehensive evaluation method are used to select the most optimal IM for the pile-supported wharf in liquefiable soils in this study. The finite element model is calibrated first to verify the model validation. Furthermore, 100 real ground motions are applied to the calibrated model as earthquake inputs. Four parameters are used as the pile-supported wharf EDPs. A total of 30 groups of IMs are evaluated from five aspects as practicality, efficiency, proficiency, sufficiency, and hazard computability. Finally, the optimal set of IMs for different EDPs with the fuzzy decision matrix are determined by the fuzzy comprehensive evaluation method.