高地应力条件下软岩大变形隧道极限位移计算模拟

Limit Displacement Simulation for Large Deformation Tunnel in Soft Ground on High Geo-stress Condition

由于受地应力水平和围岩工程性质影响,高地应力条件下软岩隧道开挖后围岩塑性变形显著,施工中常伴有支护变形侵限、大面积开裂,甚至坍塌等现象发生。如何选择合理的支护措施,有效控制软岩隧道变形并确保结构安全已成为目前地下工程界的关注焦点。施工中各阶段隧道极限位移的研究,可为该种条件下隧道设计和施工决策提供有利的技术支持。根据乌鞘岭隧道F7断层区段的实际情况、对高地应力条件下软岩大变形隧道不同施工阶段的极限位移进行研究和确定,并将研究成效应用于工程实际。

Because of influence of geo-stress level and rock property, the soft rock with high geo-stress will exhibit notable plastic deformation after tunnel excavation. The phenomena such as invasion of support structure, large area crack, even collapse often take place in construction. It has become the focus in underground engineering field how to select a proper support measure so as to control deformation of soft rock tunnel and ensure the safety effectively. Hence, research on limit displacement for every stage of tunnel construction can offer favorable theoretic basis for decision on design and construction of tunnel of the kind. Based on practical situation in F7 fault region of Wushaoling tunnel, the limit displacement in different construction stage of large deformation tunnel in soft rock on high geo-stress condition is studied and determined. The result is applied in practical project.