大断面隧道支护结构地震反应特性分析

从围岩-支护结构-地震相互作用研究思路出发,利用ADINA非线性有限元软件,通过大断面隧道施工力学及瞬时动力时程分析,研究隧道支护结构在水平(Ya)、纵向(Za)及水平-纵向(YZa)不同地震加速度作用下的位移、应力反应特性.结果表明,水平地震加速度对支护结构的水平位移、最大主应力、加速度和速度影响大,纵向地震加速度对纵向位移、有效应力、最大及最小主应力、最大剪应力、加速度和速度影响都大.在Ya=0.191 g、0.440 g或Za=0.141 g及其YZa共同作用下,大断面隧道初期支护遭到破坏,二次衬砌局部损坏;在Ya=0.440 g或Za=0.326 g及其YZa共同作用下,隧道二次衬砌遭到损坏;在Ya=0.880 g或Za=0.652 g时,隧道支护结构可能会遭到严重破坏.

Earthquake Response Properties of the Support Structure of Large Cross Section Tunnel

The response properties of displacement and stress of tunnel support structure are discussed in detail under the action of horizontal earthquake acceleration(Ya),longitudinal earthquake acceleration(Za) and horizontal-longitudinal earthquake acceleration(YZa).This discussion is based on an analysis of the surrounding rock-support structure-earthquake interaction,adoption of an ADINA nonlinear finite element and construction mechanics,and transient dynamic time domain analysis of a large cross section tunnel.Results of analysis show that:(1) Horizontal earthquake acceleration has important influence on horizontal displacement,maximum principal stress,acceleration and velocity.(2) Longitudinal earthquake acceleration has important influence on longitudinal displacement,effective stress,maximum and minimum principal stress,maximum shear stress,acceleration and velocity.(3) When Ya=0.191g and 0.440g or Za=0.141g and their combined action,the initial support of tunnel would be damaged and the local lining would have partial damage.(4) When Ya=0.440g or Za=0.326g and their combined action,the lining of tunnel would be damaged.(5) When Ya=0.880g or l Za=0.652g,the support structure of tunnel would have severe damage.