浅埋偏压连拱隧道开挖工序的数值模拟

摘要:

某山体暗挖隧道具有浅埋、偏压、大跨度、双连拱的难点。为了探究该隧道施工过程中初支结构的内力及山体边坡的稳定性变化,本项目采用plaxis 2d 岩土有限元软件对施工过程主要的15道开挖支护工序进行数值模拟。通过地层荷载法揭示各个施工步骤中衬砌结构的内力变形规律,同时基于强度折减法求出安全系数对山体边坡稳定性进行评价。根据此数值模拟结果,对该隧道结构设计提出指导性的意见。

Abstract:

A mountain underground tunnel has the difficulties of shallow burial, eccentric pressure, long span and double arch. In order to explore the internal force of the initial support structure and the stability change of the mountain slope during the tunnel construction, the project uses PLAXIS 2D geotechnical finite element software to numerically simulate the 15 main excavation and support processes during the construction process. The internal force and deformation law of lining structure in each construction step is revealed by stratum load method, and the safety factor is calculated based on strength reduction method to evaluate the stability of mountain slope. According to the numerical simulation results, some guiding opinions on the structural design of the tunnel are put forward.