The Flow-Stress Coupling Apply In Guan Jiao Tunnel

In this paper, based on the additional second-line Guanjiao tunnel of Xining to Golmud of Qinghai-Tibet Railway the engineering background, to resolve the deep tunnel design, construction and groundwater protection as a starting point, do the numerical simulation analysis of K307+00～K307+200 section of Guanjiao tunnel on the application of MIDAS-GTS finite element program.Through the inspection the report of Geo-Engineering, summed up the rock mass physical and mechanical parameters, natural and geographical conditions, lithologic features, hydrogeological conditions of the research section, compared the actual formation of the rock samples to indoor laboratory test results. Introduced the fractured rock mass, stress field and seepage field coupling and the establishment of three-dimensional finite element model of the basic theory, in order to provide a theoretical basis for numerical simulation.(1) This paper introduces the analytical model building process of the Guanjiao tunnel clearance angle, and discuss the values of the parameters and boundary conditions. Tunnel excavation and lining of the grouting of the entire process in the case of seepage field and stress field coupling is analyzed. Found that after excavation of the tunnel, the change particularly surrounding the tunnel. Around the tunnel on both sides appear the phenomenon of stress concentration, the stress of both sides up and down of the tunnel decrease sharply vault settlement, uplift arch at the end of the tunnel, surrounding rock water pressure of the tunnel and groundwater level decline in sharply, groundwater pressure in the head to penetrate the tunnel excavation. Without seepage field, showed that tunnel lining pressure increased significantly.(2) Application of groundwater dynamics and groundwater runoff modulus method on different tunnel construction program inflow of water is calculated. Under the conditions of the construction of two tunnels at the same time, taking into account stress field and seepage field coupling and does not take into account the stress field and seepage field coupling, the analysis and comparison the inflow of water of numerical simulation and testing method. Come to the conclusions considering the stress field and seepage field coupling in case of error to be far less than the stress field does not take into account coupled with the seepage field.(3) In order to protect the groundwater environment for the purpose of emissions. Analyzing and discussing the relations between difference permeability of grouting circle with water tunnel. Analysis of the operation phase of the tunnel, the tunnel under the different drainage flow to get the water level decline and the scope of dewatering funnel.