基于UDEC的岩脉侵入角度对隧道安全影响分析

Analysis of influence of dike intrusion Angle on tunnel safety based on UDEC

为探究岩脉侵入角度对隧道开挖的影响,文章以泸石高速石棉隧道开挖时地层遭遇不同角度岩脉侵入为工程背景,通过UDEC离散元计算,总结岩脉侵入角度对隧道开挖的影响,给出有效处理措施,并得出以下结论:岩脉和被侵入岩体界面易发生塑性滑移,隧道开挖后岩脉区围岩变形最大,且岩脉区围岩有开裂、滑移和隆起现象,围岩变形随角度的减小而减小。边墙与仰拱连接处轴力、剪力、弯矩均最大,安全系数最小,三种工况均在0.3左右。衬砌轴力、剪力的最大值随角度减小而增大,弯矩受角度的影响较小。岩脉区域的安全系数在向着岩脉倾斜方向更小。岩脉侵入区域隧道开挖应采用岩脉区域局部注浆、封闭仰拱、增大衬砌厚度三种方法来加固围岩和提高衬砌承载能力。

In order to explore the influence of dike intrusion Angle on tunnel excavation,based on the engineering background that the stratum encountered dike intrusion from different angles during the excavation of Lushi high-speed asbestos tunnel,this paper summarized the influence of dike intrusion Angle on tunnel excavation through UDEC discrete element calculation,and proposed effective treatment measures.Conclusions are as follows:The interface between the dike and the invaded rock mass is prone to plastic slip,and the surrounding rock deformation in the dike area is the largest after tunnel excavation,and the surrounding rock in the dike area has cracking,sliding and uplift phenomena,and the deformation of the surrounding rock decreases with the decrease of the Angle.The axial force,shear force and bending moment of the joint between the side wall and the invert are the largest,and the safety factor is the smallest,and the three working conditions are about 0.3.The maximum axial force and shear force increase with the decrease of the Angle,and the bending moment is less affected by the Angle.The safety factor of the dike area is smaller in the direction of dike inclination.Three methods of local grouting in dike area,closing invert and increasing lining thickness should be adopted to strengthen surrounding rock and improve the bearing capacity of lining.