Estimating the Probability of Failure of a Dike due to Post-Liquefaction Settlements

ABSTRACT: The objective of this study is to estimate the probability of failure of a simplified dike system due to excessive post-liquefaction reconsolidation settlements of the foundation soils. The results are presented in the form of seismic fragility curves, which estimate the probability of failure of a performance level as a function of peak ground acceleration. The curves are obtained by combining 1-dimensional liquefaction triggering analyses with Monte Carlo simulations, with soil strength being modelled as a 2-dimensional spatially correlated random field. The study considers four performance levels, determined in accordance with seismic design guidelines and field performance data. Additionally, the effects of horizontal correlation length and dike system length on the estimated probabilities are explored. Site-specific seismic hazard models may then be used to obtain the total probability of dike failure over its design lifetime.