Analysis of influence of dike intrusion Angle on tunnel safety based on UDEC
In order to explore the influence of dike intrusion Angle on tunnel excavation,based on the engineering back-ground 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 deform-ation 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 ben-ding 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.
tunnel engineeringalteration zone of intrusive body dikeUDEC discrete elementtreatment measures