深埋交叉隧道动态施工力学行为研究

分离式独立双洞之间的横通道开挖,再一次引起主隧道围岩和支护结构的应力释放与重分配,引起交叉段附近岩体与支护结构力学行为发生变化。结合高地应力区深埋隧道工程,通过3D弹塑性有限元数值仿真模拟,分析横通道不同施工方案和动态施工过程对主隧道围岩与初期支护结构力学行为的影响。分析结果显示,横通道的开挖对围岩应力和位移影响较大,对交叉侧主隧道侧壁初期支护应力及交叉对侧主隧道侧初期支护3σ和XY平面的剪应力影响较大。为深埋隧道交叉段监控量测系统的设计、施工方案优化及安全控制提供了依据。

Dynamic Construction Mechanical Behavior of a Deeply Buried Intersection Tunnel

Excavation of an intersection tunnel between independent double tunnels leads again to stress release and redistribution in the surrounding rock and the support structure of the chief tunnel,resulting in change of mechanical behavior of the rock mass and the supporting structure near the intersection.Considering deeply-buried tunnel engineering in high geo-stress areas,we analyzed the mechanical behaviors of the surrounding rock,the initial support system of the chief tunnel with different construction schemes,and dynamic construction processes of the intersection tunneling using 3D elastic-plasticity finite element numerical simulation.The results of numerical analysis show that intersection tunneling greatly affects the following: the stress and displacement of the surrounding rock,the initial supporting stress for the side wall of the chief tunnel on the intersection side,and the maximum and shear stresses in XY plane on the side opposite the intersection.This study offers references for design of the monitoring system,construction scheme optimization,and safe control of deeply-buried tunnels.