PUSH-OVER ANALYSIS FOR CUT AND COVER TUNNELS IN CONSIDERATION SEQUENTIAL CHANGES OF INTERACTION BETWEEN GROUND AND STRUCTURE

Abstract

 This paper proposed a pushover analysis method for cut and cover tunnels that considers the interaction between the ground and the structure. In this method, seismic force and soil stiffness were evaluated based on the primary mode shape of the surface soil at each time step. The obtained soil deformation was then sequentially applied to the tunnel by a static non-linear analysis. It was confirmed through series of validation analysis that the seismic force and soil stiffness obtained by the proposed method showed good agreement with those obtained from dynamic ground response analysis. By using the proposed method, it is now possible to accurately calculate the section force of elements and damage process of the tunnel under earthquake without carrying out dynamic response analyses. In addition, this method is also applicable for the seismic design and performance verification of tunnels.