Performance Evaluation of Pile-Supported Wharf under Seismic Loading

Abstract

Past earthquakes have demonstrated that port facilities suffer extensive seismically induced damage due to poor foundation and backfill soil that are common in waterfront environments. Focusing on pile-supported wharves, this study evaluates seismic behavior of port structures recognizing that most of the parameters controlling the properties of soil are of a random nature. The response of such structures inherently presents a complex soil-structure interaction (SSI) problem involving ground shaking, pile-failure mechanism, and liquefaction and lateral spreading in backfill and sand layers. In this study, using a representative model of a typical pile-supported wharf in the west coast of United States and considering an ensemble of ground motions with different hazard levels, effect of soil parameter uncertainty on seismic response is evaluated. For numerical simulations, an effective stress analysis method has been utilized. In order to investigate the effect of soil parameter uncertainty on seismic response, random samples are generated using Latin Hypercube Sampling and nonlinear time history analysis is carried out repeatedly for each realized sample. Finally, the effect of parameter uncertainty is demonstrated in terms of seismic fragility curves. The results of this study can be utilized to evaluate the seismic vulnerability of similar pile supported wharves.