考虑流固耦合的香炉山隧道围岩稳定性分析

STABILITY ANALYSIS OF XIANGLUSHAN TUNNEL SURROUNDING ROCK IN CONSIDERATION OF FLUID-STRUCTURE COUPLING

根据香炉山隧道实际围岩支护和含水条件建立了隧道开挖支护模型,考虑水压和初期支护的影响,对Ⅳ级围岩、Ⅴ级围岩和Ⅴ级围岩富水区的隧道开挖收敛位移进行了模拟计算,并和现场监测所得隧道最终位移数据进行了对比分析,验证了数值模拟方法的准确性。之后分析了隧道围岩水压、埋深、侧压力系数以及开挖方式对隧道开挖最终收敛位移的影响。结果表明,随着围岩水压的增长,隧道最终收敛位移开始呈线性增长,之后增长速率变大至隧道破坏;随着开挖隧道埋深的增加,隧道拱顶沉降和水平收敛的最终位移呈线性增长;随着围岩侧压系数的增加,隧道水平收敛的最终位移呈线性增长,拱顶沉降的最终位移小幅度减小;相比台阶法开挖,中隔壁墙法和环形开挖预留核心土法对于隧道的位移收敛具有更好的控制效果。

In this paper,a tunnel excavation support model was established according to the actual surrounding rock support and water bearing condition of Xinglushan tunnel.Considering the influence of water pressure and initial support,the convergence displacement of the tunnel in IV-grade surrounding rock,V-grade surrounding rock and the water-rich area of the V-grade surrounding rock were simulated and compared with the final displacement data of the field monitoring.The analysis results verify the accuracy of the simulation method.Then,the influence of surrounding rock water pressure,buried depth,lateral pressure coefficient and excavation method on the final convergence displacement of tunnel were analyzed.The results show that the final convergence displacement of the tunnel begins to linearly increase with the increase of water pressure,and then the increase rate increases until the tunnel becomes unstable and fails.With the increase of tunnel depth,the final convergence displacement in vertical and horizontal directions increases linearly.With the increase of the lateral pressure coefficient of surrounding rock,the final convergence displacement of the tunnel in the horizontal direction increases linearly,while the final convergence displacement in the vertical direction decreases slightly.Compared with the step excavation method,the center diaphragm method and ring cut method have better control effect on the convergence displacement of the tunnel.