逆断层错动下隧道衬砌的力学响应

Mechanical Response of Tunnel Lining Forced by Reverse Fault Dislocation

以穿越新疆大旱沟西岸逆断层的拟建隧道为工程依托,采用大比例尺活断层错动加载系统开展室内模型试验,探明在逆断层错动作用下隧道分段衬砌力学响应特征及裂缝形态分布规律。通过建立三维地层-结构模型,模拟分析逆断层错动下不同衬砌分段长度时衬砌的变形特性及力学特征。结果表明:在逆断层错动下,上盘竖向位移随错动距离增大而增大,由逆断层错动导致的衬砌裂缝以纵向裂缝为主,裂缝主要位于边墙、墙脚以及仰拱中心;断层错动后衬砌相邻节段变形不连续,变形缝有利于提高隧道结构的抗错动性能;跨断层中心竖向截面处衬砌第一主应力随断层错动距离增加而近似呈线性增大,且衬砌分段长度越大则衬砌内力越大。

Relying on the proposed tunnel crossing the active fault on the west bank of Dahanggou in Xinjiang region,indoor model tests were carried out using a large scale active fault dislocation loading system to verify the mechanical response characteristics of tunnel lining and the distribution law of crack morphology under the action of reverse fault dislocation.the deformation characteristics and mechanical characteristics of the lining with different lining section lengths under reverse fault dislocation are simulated and analyzed by establishing the three-dimensional stratum structure model.The results show that,under the reverse fault dislocation,the vertical displacement of the hanging wall increases with the increase of the displacement distance.The lining cracks caused by the reverse fault dislocation are mainly longitudinal cracks,which are mainly located in the side wall,wall foot and inverted arch center.The deformation of adjacent segments of the lining is discontinuous after fault dislocation,and the deformation joint is beneficial for improving the anti-dislocation performance of the tunnel structure.The first principal stress of the lining at the vertical section of the cross fault center increases approximately linearly with the increase of fault dislocation distance,and the larger the length of the lining section,the greater the internal force of the lining.