正断层下隧道结构受力特征及设防长度研究

以乌鲁木齐市跨活动断层轨道交通1号线地铁隧道为研究对象，根据活动断裂带近场区几何学特征与运动学特征并结合区域地震构造条件，采用理论分析和数值模拟综合方法，针对活动正断层粘滑错动下隧道衬砌结构在不同因素条件时的纵向力学响应，系统计算分析了整体式隧道衬砌结构纵向应变、主应力、裂缝和围岩-初期支护附加接触力等分布规律。结果表明:结构埋深从10 m增至20 m，隧道结构设防范围无明显变化；断层倾角从60°增至80°，隧道结构设防范围逐渐减小。

Study on Mechanical Characteristics and Fortified Length of Tunnel Structure under Normal Slip Fault

Taking the subway tunnel of Urumchi Metro Line 1, which steps over active fault, as the study object, the paper, on condition of the geometric and kinematic characteristics of near field region thereof and the regional seismotectonics, and on account of the longitudinal mechanical response in different cases of tunnel lining structure under the action of strike-slip movement of the active normal fault, calculated and analyzed by means of theoretical analysis and numerical simulation the laws how the longitudinal strain, principle stress, cracks and additional contact force between surrounding rock and primary support are distributed in the integral tunnel lining structure. The result shows that, where the buried depth increases from 10 m to 20 m, the tunnel structure’s fortified limit has no obvious change; and where the fault dip increases from 60° to 80°, the fortified limit is reduced gradually.