Seismic Fragility Analysis for Sheet Pile Wharves — Case Study of the Hualien Harbor in Taiwan

The seismic fragility curves represent the conditional probabilities that the structural damage meets or exceeds the specified damage states at various levels of the ground motion parameters, such as peak ground acceleration (PGA). In this study, the seismic fragility analysis for the sheet pile wharves of the Hualien Harbor in Taiwan was performed. The finite element analysis software PLAXIS was adopted for the nonlinear dynamic analysis. The time histories of several representative earthquake events that actually occurred in Taiwan, including the 1999 Chi-Chi Earthquake, were scaled to various PGA levels as the input motions. Then the seismic responses of the sheet pile wharves subjected to these earthquakes of different intensities were obtained. It is assumed that the maximum residual displacement at the top of the sheet pile wall is lognormal distributed. Thus, the conditional exceedance probabilities of each specified damage state at different levels of PGA were estimated according to the displacement threshold value of each damage state, and the fragility curves were deduced. Moreover, these fragility curves were parameterized assuming they can be well approximated by the lognormal cumulative probability function, which is important for the rapid estimation of earthquake loss