巴基斯坦卡拉奇核电站排水隧洞变形模拟分析

Deformation Simulation Analysis of Drainage Tunnel in Karachi Nuclear Power Station Pakistan

目前,国内对于普通隧洞已经有了深入的研究,然而对于复杂的软岩排水隧洞工程,国内的研究相对较少,因此有必要对软岩排水隧洞变形分析进行研究,把不同埋深下软岩隧洞的变形作为研究重点。运用三维有限差分软件FLAC3D,根据巴基斯坦卡拉奇k2/k3核电厂排水隧洞支护参数与地质资料,对不同埋深下隧道初期支护与围岩竖向位移进行了仿真模拟,得出随隧洞埋深增大,初支压应力值逐渐增大,并且应力的变化率逐渐减小,初支压应力最大值位于两侧拱腰处。隧洞开挖后,初支受力达到其材料参数允许值,隧洞最大变形值大致稳定,因此建议其安全控制基准值设定为55 mm。与原设计对比,围岩位移与初支受力均略超过设计的安全范围,因此需要进行适当的加强,以保证工程的质量与安全。

At present,there has been in-depth research on ordinary tunnels in China,but there is relatively little research on complex soft rock drainage tunnel projects in China,so it is necessary to study the deformation analysis of soft rock drainage tunnels,focusing on the deformation of soft rock tunnels under different buried depths.In this paper,the three-dimensional finite difference software FLAC3 D is used to simulate the initial support of the tunnel and the vertical displacement of surrounding rock under different buried depths,according to the support parameters and geological data of the k2/k3 nuclear power plant in Karachi,Pakistan.After the tunnel is excavated,the stress of the primary support reaches the allowable value of its material parameters,and the maximum deformation value of the tunnel is approximately stable,so it is suggested that the safety control reference value should be set to 55 mm.Compared with the original design,the displacement of surrounding rock and the stress of primary support are slightly beyond the design safety range,so appropriate reinforcement is needed to ensure the quality and safety of the project.