分析了静应力场对隧道及地下结构动力响应产生的影响。指出了静应力场的几种处理方法以及在隧道列车振动分析中宜采用的计算方法。以某一隧道为例,计算了其在列车动力荷载作用下的反应。计算表明:静应力场宜将高斯点应力和节点荷载同时输入。若仅输入高斯点应力或节点应力,而不输入节点荷载,以此为初始条件进行隧道列车荷载动力计算将产生错误的结果;为消除静力残余不平衡节点力在动力分析中影响,宜先不作用列车振动荷载,而是在静力残余不平衡节点力作用下进行动力分析,待体系逐步趋于静平衡状态后再施加动力荷载进行求解。
The influence of the initial static stresses on dynamic responses of tunnels and underground structures is studied. Some disposal methods of the initial static stresses are presented and a preferable method is recommended in the analysis of train vibration responses of tunnels. Dynamic responses of a tunnel due to the train vibration are calculated. Results indicate that the initial condition in dynamic analysis is not only the input Gauss point stresses but also the input nodal loadings, or mistakes will be aroused. In dynamic calculation of anterior time steps, the static residual forces should be only acted. When the system responses incline to static states, the vibration loading is input and the dynamic calculation of remaining time steps is continued.