层状岩体围岩变形破坏特征及稳定性评价

Deformation characteristic and stability analyses of layered rockmass

摘要: 层状岩体是地下工程中经常遇到的一种岩体,具有明显的各向异性力学性质,其变形破坏特征与均值岩体相比表现得更为复杂。根据共和隧道地质调查和地应力量测的资料分析,隧道围岩偏压现象与地应力和岩性有极大的相关性。通过对隧道初期支护开裂段围岩位移收敛、围岩接触压力、锚杆轴向力监测和松动圈探测,其结果表明,围岩变形及应力和松动圈都在右拱肩处最大,即靠河侧大于靠山侧,与初始地应力的最大主应力方向不一致。因此,通过现场监测提前了解围岩-支护结构的变形及受力状况,及时修改了支护参数,避免了隧道垮塌等恶性事件的发生,从而有效指导了隧道施工和设计。

Abstract: Layered rockmass which is always met in underground engineering has obvious anisotropic mechanical properties.Compared with the isotropic rockmass,its failure features are more complicated.According to the geologic reconnaissance and in-situ stress measurement of Gonghe tunnel,the tunnel rockmass bias pressure has close relationship with in-situ stress and lithology.By the monitoring and detecting of the convergence displacement of surrounding rock in section of failure of primary support,surrou...