Seismic fragility analysis of pile-supported wharves with the influence of soil permeability

Past seismic events have shown that pile-supported wharves are susceptible to severe damage during earthquakes, and thus it is important to assess the seismic performance of pile-supported wharves. Seismic fragility analysis is recognized as an effective means for seismic performance assessment of infrastructural systems exposed to seismic hazards since it quantifies the probability of seismic damage conditioned on the various ground motion intensity levels. This study systematically investigates the seismic fragility of a large-scale pile-supported wharf at both component and system levels. It is well known that pile-supported wharf is a typical soil-pile structure system, and the soil-pile-structure interaction will significantly affect its seismic performance. In this regard, a solid-fluid, fully-coupled nonlinear finite element (FE) model is developed for the seismic analysis of this large-scale pile-supported wharf. Additionally, to determine the quantitative seismic demand bounds for different damage states, this study proposes the use of the pushover analysis-based procedure rather than engineering judgment or engineering common sense which is subjective to a degree. Furthermore, the soil permeability is another parameter that may evidently influence seismic fragility of wharf structures, so its influence is also discussed in detail through parametric studies.