Abstract Fault fracture zones are adverse geological conditions often encountered in the constructions of mountain tunnels. Extensive structural damage to the mountain tunnels in adjacent to the fault fracture zones has been documented in the past earthquakes. In current work, three-dimensional numerical model of a water conveyance tunnel crossing multiple active strike-slip faults was established to assess the structural damage with consideration of four primary influence factors: the magnitude of fault movement, the distance between adjacent fault planes, the tunnel-fault intersection angle and the mechanical properties of the rock mass in the fault fracture zone. Two quantitative damage indices, namely, the overall structural damage index and the concrete lining crack width, are proposed in this study to investigate the structural integraty and the serviceability of the water conveyance tunnel subjected to fault movements. The numerical results indicate that the cross-sectional damage of the tunnels primarily concentrated in the vicinities of the fault planes, and the boundaries between the fault and the competent rock. With the increase of the distance between adjacent fault planes, the structural damage of the tunnel in the region near the center of the fault fracture zone rapidly decreases. The tunnel-fault intersection angle also significantly affects the performance of the tunnel under fault movement. Moreover, the increase of surrounding rock mass stiffness in the fault fracture zone reduces the extension but increases the severity of damage to the tunnel lining. Overall, the numerical results of this study provide a better understanding of the response of mountain tunnels under multiple strike-slip fault movement.

中文翻译：

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多次走滑断层运动作用下断层断裂带山地隧道结构损伤评价

摘要 断层断裂带是山地隧道施工中经常遇到的不利地质条件。在过去的地震中，记录了与断层断裂带相邻的山地隧道的广泛结构损坏。在目前的工作中，建立了穿越多条走滑活动断层的输水隧道三维数值模型，考虑四个主要影响因素：断层运动幅度、相邻断层面之间的距离、断层断裂带隧道-断层相交角及岩体力学特性. 两个定量损伤指标，即整体结构损伤指数和混凝土衬砌裂缝宽度，本研究提出了研究受断层运动影响的输水隧道的结构完整性和适用性。数值结果表明，隧道断面损伤主要集中在断层面附近，以及断层与成岩之间的边界。随着相邻断层间距离的增加，断层断裂带中心附近区域的隧道结构破坏迅速减小。隧道-断层相交角度也显着影响断层运动下隧道的性能。此外，断层断裂带围岩刚度的增加减少了延伸，但增加了隧道衬砌损坏的严重程度。全面的，