斜滑断层不均匀错动下隧道三维力学响应计算模型

A Three-dimensional Mechanical Response Calculation Model for Tunnels under Uneven Dislocation of Oblique Slip Fault

针对穿越斜滑断层隧道力学响应问题,采用有限差分法求解非线性荷载作用下的弹性地基梁挠度微分方程,建立考虑斜滑断层不均匀错动特征的隧道三维力学响应理论计算模型。以“1·8门源地震”大梁隧道为工程背景,对理论模型的准确性及合理性进行验证,并分析断层倾角、隧道-断层交角对隧道力学响应的影响。结果表明,理论模型计算结果与数值模型计算结果及现场实际震害情况吻合良好;随着断层倾角、隧道-断层交角的变化,穿越斜滑断层隧道的各向(水平向、竖向、纵向)变形分量不断改变,其力学响应特征复杂。

In view of the mechanical response of tunnels crossing oblique slip faults,the finite difference method is used to solve the differential equation of elastic foundation beam deflection under nonlinear loads,and the theoretical calculation model of three-dimensional mechanical response of tunnels with considering the uneven dislocation characteristics of oblique slip faults is established.Based on the Daliang Tunnel affected by the"Menyuan earthquake on January 8th",the accuracy and the rationality of the theoretical model are verified,and the effects of fault dip angle and the tunnel-fault included angle on the mechanical response of the tunnel are analyzed.The results indicate that the theoretical model calculation results are in good agreement with the numerical model calculation results and the actual seismic damage conditions on site;following the change of the fault dip angle and the tunnelfault included angle,the deformation components of the tunnel crossing the oblique slip fault at various directions(horizontal,vertical,and longitudinal)will change continuously,and its mechanical response characteristics are complicated.