Seismic performance evaluation of a pile-supported wharf system at two seismic hazard levels

This study presents a framework for assessing the seismic performance of a pile-supported wharf at different seismic hazard levels. A refined Three-Dimensional (3D) Finite Element (FE) model is conducted using the open-source computational platform OpenSees. The modeling strategies of the refined numerical model are given in detail, including refined modeling of free-field boundaries and soil-pile interaction. Two seismic hazard levels adopted by the design standard for seismic design of piers and wharves (ASCE 2014) are considered, namely, Contingency Level Earthquake (CLE) and Design Earthquake (DE). The seismic performance of the wharf-ground system is systematically explored in the following two aspects. First, the evaluation of seismic performance is based on the time history response for CLE (and DE) motion. Second, the seismic performance is assessed by averaging maximum response for all 28 DE and CLE motions. The results from this study reveal that (i) the seismic response of the wharf-ground system is larger under a DE motion than under a CLE motion; (ii) the pile foundation with a short free length is more vulnerable to damage for both seismic hazard levels; and (iii) the fiber strains of piles are significantly lower than the strain limits in the design standard (ASCE 2014).