Seismic Response Analysis Of Shield Tunnel To Large Fault Movements

As one of those important research topics in tunnel engineering,a remarkable amount of literatures have been reported to study responses of tunnel to large fault movements.However,most of the researches of shield tunnels across the fault make the shield tunnel equivalent to the single and homogeneous material,which doesn't take into account the simulation of joints.Meanwhile,researches are still incomplete,adopting solid element in modeling techniques.Thus,it is of important theoretical significance and engineering guidance value to study the seismic safety responses of shield tunnel across the fault using a more rational model.Based on those previous studies,this paper deals with seismic response analysis of shield tunnel to large fault movements by shield tunnel shell-spring models,in which the equivalent boundary is applied at the boundary of tunnel,and the article is organized as follows.Firstly,based on the previous studies,this paper adopts the methods of shield tunnel spring coefficient proposed by Huang Zhonghui to build the shield tunnel shell-spring three-dimensional model,in which the interaction of tunnel and soil is considered by soil spring element,and equivalent boundary is modeled by a series of equivalent spring at the two ends of shell model.Secondly,we simulate the movement of shield tunnel under normal-slip fault,reverse-slip fault and strike-slip fault.Thirdly,we study the mechanical deformation and failure characteristics of shield tunnel by the three fault movements.The results show that different types of fault movements generate different effects on shield tunnel,normal-slip fault movement bring more tensile stress,which is disvantage for tunnel structure.Reverse-slip fault movement causes compression destruction,which is profitable for mechnics performance.Strike-slip fault movement takes shearing effect on shield tunnel.Moreover,tunnel under the reverse fault movement can resist larger fault displacement,normal fault comes second and strike fault take the third place.