Abstract

Info

Author(s):: GAO Feng; SUN Chang’xin; DING Qi-le; TAN Xu-kai; HE Qing-bi; 1. State Key Laboratory Breeding Base of Mountain Bridge and Tunnel Engineering, Chongqing Jiaotong University, Chongqing 400074, China; 2. School of Resources & Environment, North China University of Water Resources and Electric Power, Zhengzhou 450011, Henan, China

Keywords:: tunnel engineering; soil above the tunnel; earthquake action; calculation method; mode of action; comparative analysis

Abstract:: The current calculation method of seismic force provided for soil above the tunnel lining was not accurate enough, which still used hydrostatic pressure arch height to determine the earthquake height of soil above the lining. Combined finite element method with analytical calculation, this paper defined the earthquake height H_P of soil above the tunnel by researching the change of vertical stress above the tunnel along depth before and after earthquake, gave out the formula for H_P considering tunnel span, rock types, shape and depth of the tunnel and many other factors, determined the forces acting on the lining, cleared its mode of action, and verified its applicability. The results show that the distribution of analytical calculation results is same to that of the results gained from finite element method. The H_P calculated by tunnel specification is bigger when the tunnel depth is small; on the other hand, the H_P calculated by tunnel specification is smaller when the tunnel depth is big. The method used to define H_P is feasible. The action mode on lining is distributed over half-arch lining as tangential force. The results can provide a reference for seismic calculation of tunnel.