断层竖向错动作用下隧道力学响应数值模拟研究

Numerical Simulation of Mechanical Response of Tunnel Under Vertical Fault Dislocation

采用有限单元方法数值模拟研究断层竖向错动位移、断层错动速率、断层宽和断层摩擦对断层错动下隧道力学响应的影响规律。结果表明:断层竖向错动位移显著改变隧道断层截面第1应力的大小和分布。断层错动隧道断层截面出现最大第1主应力,不受断层竖向错动位移、断层错动速率、断层宽度和断层摩擦的影响。断层错动影响范围主要受到断层位移和宽度的影响,受断层错动速率和断层摩擦系数影响较小。断层错动速率越快,断层摩擦系数变化对应力峰值增加的影响越明显。主动盘内隧道截面衬砌第1主应力随断层错动速率增加而增加,但是断层截面的第1主应力随断层速率增加,先增后减,在0.1m/s断层速率条件下,达到最大值。

The finite element method was used to simulate the influence of vertical fault displacement,fault dislocation velocity,fault thickness and fault friction on the mechanical response of tunnel.The numerical simulation shows that the vertical fault displacement significantly changes the size and distribution of the first stress in the fault section of tunnel.The maximum first principal stress exists in the fault section of the fault staggered tunnel,which is not affected by the vertical displacement,velocity,thickness and friction of the fault.The affected scope for fault dislocation is mainly influenced by fault displacement and width,but less did by fault dislocation velocity and fault friction coefficient.The faster the fault dislocation velocity is,the more obvious the influence of the change of fault friction coefficient on the increase of stress peak value is.The first principal stress of the lining of the tunnel section in the active panel increases with the fault dislocation velocity,but the one of fault section increases first and then decreases with the fault dislocation velocity,and reaches the maximum value at the one of 0.1 m/s.The research results of this paper present a reference to reduce the failure of tunnel under fault dislocation.