走滑断层错动下山岭隧道关键断面变形及损伤演化

山岭隧道受选线制约大多要穿越活动断裂带，而活动断裂带的运动会对与之相交的隧道结构的安全产生影响。为此，对穿越走滑断层的隧道在地震中所遭受的破坏展开调研具有现实意义。以滇中引水工程香炉山隧洞为背景，建立隧道-断层三维有限元分析模型，研究走滑断层错动下隧道关键断面的变形特征。基于所建立的有限元模型，采用相对位移法对断层错动量、断层破碎带宽度和穿越角度的影响进行参数分析。研究结果表明：穿越角度为45°时，截面的变形模式为水平椭圆，而穿越角度为135°时，截面的变形模式为直立椭圆；随着断层破碎带宽度的增加，位于断层中间位置处的隧道截面的变形程度减小；走滑断层错动下，隧道截面变形最为严重的区域出现在拱顶和拱底，在进行山岭隧道的设计时需要重点关注。

Deformation and damage evolution of critical cross section of mountain tunnels under strike-slip fault movement

Mountain tunnels often pass through active fault zones due to the restriction of route planning. The activities of fault zones affect the safety of the tunnel structure that intersects them. Therefore, post-earthquake reconnaissance was conducted to investigate the damage characteristics of tunnels crossing strike-slip faults. Based on Xianglu Mountain tunnel of water diversion project in central Yunnan province, a three-dimensional finite element analysis model of tunnel-fault system was established to investigate the deformation characteristics of critical cross section of tunnel under strike-slip faulting. Based on the established finite element model, parametric analysis was performed to investigate the effects of the fault displacement, fault width and the intersection angle using the relative displacement method. The results show that the deformation mode of cross section is horizontal ellipse for the intersection angle of 45°. For the intersection angle of 135°, the deformation mode of cross section is upright ellipse. The deformation of tunnel cross section located in the center of the fault fracture zone is reduced with the increase of the fault width. The areas with the most severe deformation in the cross section of tunnel appear in the vault and the bottom of the tunnel lining under strike-slip faulting, which needs to be concerned in the design of mountain tunnels.