Probabilistic Seismic Demand Models of Circular Tunnels Subjected to Horizontal Ground Motions Based on 2D Dynamic Analyses

This paper develops the probabilistic seismic demand models of circular tunnels under the transversal seismic load. The uncertainties of ground motion, soil profile, tunnel depth, and lining size are considered. Since the quasi-static analyses may significantly underestimate the seismic responses of tunnels, the results of dynamic numerical analyses are adopted to construct probabilistic models that are more accurate. The constructed model is unbiased and can facilitate the fragility analysis of tunnels. As a demonstration, the proposed probabilistic models are used to estimate the seismic fragility curves of a particular tunnel.