Stochastic Dynamic Analysis and Time-Dependent Reliability Assessment of Pile-Supported Wharves Based on PDEM

Seismic assessment is essential to maintain pile-supported wharves (PSW) functionality and limit earthquake losses. However, existing studies have not fully addressed the stochastic dynamic response of PSW systems and the evolution of their time-dependent seismic reliability. To address this, a Probability Density Evolution Method (PDEM)-based framework is developed to quantify reliability degradation under stochastic excitation. The results indicate pronounced non-Gaussian evolution of the response probability density over time, including broadening, peak reduction, skewness, and multimodality. Consistently, the system reliability exhibits a non-smooth, stepwise decline, implying that the underlying response process deviates from conventional Poisson or Markovian assumptions.