宽大断层构造破碎带内隧道施工稳定性分析

Stability Analysis of Tunnel Construction in Wide Fault Structural Fracture Zone

以穿越断层构造破碎带的哨房丫口隧道为工程背景,应用数值模拟方法,对枯水期、正常降雨、丰水雨季3种工况下隧道围岩位移变形规律和应力应变特征进行分析,结果表明,在3种工况下隧道开挖至断层构造破碎带约15m时隧道拱顶竖直位移和最大应力开始增加,越靠近构造带位移和应力越大,当进入构造带与围岩交界位置时,位移和应力达到最大值,远离构造破碎带时位移和应力明显减小;在相同条件下,丰水季节位移和应力最大、正常降雨次之、枯水季节最小,隧道拱顶竖直位移和最大应力随富水程度增加而增大。

Taking Shaofangyakou Tunnel passing through fault structural fracture zone as the engineering background, the displacement and deformation law and stress-strain characteristics of tunnel surrounding rock under three working conditions of dry season, normal rainfall and rainy season are analyzed by numerical simulation method. When the tunnel is excavated to the fault structure fracture zone about 15 m, the vertical displacement and maximum stress of the tunnel crown begin to increase, and the closer the tunnel is to the structural zone displacement and deformation, the larger the stress is, the maximum displacement and stress will be when entering the junction of the structural zone and surrounding rock, and the displacement and stress will obviously decrease when it is far away from the structural fracture zone. Under the same conditions, the displacement and stress are the maximum in wet season, followed by normal rainfall and minimum in dry season. The vertical displacement and maximum stress of tunnel vault increase with the increase of water enrichment.