A study on the seismic behavior of underground tunnels, considering dynamic fault rupture, through large-scale finite element analysis

摘要

Recently, analyzing the effects of fault displacements on a fault-crossing tunnel has been in focus, in regard to vulnerability assessment, as well as the design of safe underground structures. The current study involves a large-scale seismic rupture simulation of an entire fault, tunnel and the surrounding crustal rock area. The parallel finite element program FrontISTR, was modified to include RC nonlinearity and fault modelling in the current study. The model was prepared using solid elements for the crust and joint elements for the fault surface. The tunnel is modelled using non-linear concrete solid elements and anisotropic plane-stress reinforcement steel elements. Through numerical simulation, the influence of considering dynamic fault rupture and tunnel non-linearity are investigated. This study highlights the importance of considering dynamic fault rupture with respect to the damages incurred by the tunnel, realized through its displacement mode, material degradation and crack patterns.