强渗流条件下山岭分离式隧道围岩变形分析

Surrounding Rock Deformation Analysis of Mountains Separated Tunnel under Strong Seepage Condition

强渗流作用导致山岭分离式隧道发生严重沉降。针对隧道渗流参数难以确定的现状,提出了一种符合山岭分离式隧道在强渗流条件下的围岩参数计算方法;通过设置多组参数(渗透系数和孔隙率)进行数值模拟,将模拟结果与现场实测数据进行对比验证,得到强渗流条件下隧道参数值,并分析了不同渗流参数条件下山岭分离式隧道围岩孔压分布、水平侧移和隧道沉降规律。研究表明:渗透系数和孔隙率决定着孔隙水压力和渗流量的发展,对隧道围岩变形影响较大;侧压力系数对围岩变形的影响也呈现明显规律,随着侧压力系数的增加,隧道变形值减小,收敛达到平衡稳定的时间也明显减小。

Serious sedimentation of mountains separated tunnel appear under strong seepage. In view of the situation that the tunnel seepage parameters are difficult to determine,this paper proposes a calculation method of the parameters of adjoining rock to meet mountains separated tunnel under the condition of strong seepage; By setting up multiple sets of permeability coefficient and porosity to have numerical simulation,the simulated results are also compared with the field test data to get the parameter values of the tunnel under the condition of strong seepage,and analyze the rule of pore pressure distribution of surrounding rock,horizontal displacement and tunnel subsidence settlement of mountains separated tunnel under the different condition of seepage. Research shows that the coefficient of permeability and porosity determines the development of pore water pressure and seepage flow,the impact on the surrounding rock deformation is large; The lateral pressure coefficient on the deformation of surrounding rock also presents obvious regularity; with the increase of lateral pressure coefficient,the value of tunnel deformation decreases and the time of convergence to stable equilibrium was also significantly reduced.