浅埋大断面隧道围岩稳定性数值模拟及现场监控量测

Numerical simulation and field monitoring of surrounding rock stability of shallow-buried tunnel with large-section

浅埋大断面隧道由于开挖断面大、埋深浅、围岩物理力学性质差,开挖后容易产生大变形及变形速度过快,严重影响施工进度和施工安全。本文基于RFPA数值模拟软件,模拟了隧道开挖时掌子面围岩的应力、位移及变形破坏特征;在数值模拟的基础上采用应力和声发射联合法对隧道现场开挖围岩的应力和岩体应力调整进行监测,分析开挖过程中岩体变形与时间和空间的变化关系,得到了掌子面开挖及施工中岩体的变形和变化规律,可以为支护措施的设计与支护时机的选取提供一定的参考建议。

Due to the large excavation area, the shallow buried depth and the poor physical and mechanical properties of the surrounding rock of shallow-buried tunnel with large-section,it is easy to produce rapid and large deformation after tunnel excavation,which affects the construction progress and construction safty seriously. Based on RFPA numerical simulation software,the stress,displacement and deformation failure characteristics of the surrounding rock in tunnel excavation are simulated. Then,the combined method of stress and acoustic emission is used to monitor the stress of the surrounding rock and the adjustment of rock stress,so as to analyze the relationship between the deformation of rock mass and the time and space in the process of excavation. Finally,the deformation and change law of the rock mass in the face excavation and construction are obtained,which could provide some suggestions for the design of support measures and the selection of support time.