Construction Monitoring Of The Small Spacing Tunnel And Numerical Simulation Of Wall Rock's Stability

This paper which based on the monitoring measurement design of JiuLing spacing tunnel, gained in the construction process the monitoring measurement information; according to the information and the laws gained through experience and theory,the paper analyzes to estimate the rock stability of ground-support system and adjust the support time and the support parameter appropriately. In this paper, plane computation module of small spacing tunnels is built according to practical projects.The paper gives a description of numerical simulation of small spacing tunnels cutting and timbering,and the paper analyzes small spacing tunnels into its constituent parts, which include displacement field,stress field,preliminary bracing of shotcrete and axial force of roofbolt.And using 3D FEM model to simulate the vary character of surrounding rock stress,support bearing, and ground surface settlement on the construction process.This paper mainly includes contents as follows:1 .This paper introduces survey of JiuLing spacing tunnel.2.This paper introduces New Austrian Tunnelling Method which used to be construction of small spacing tunnel and expatiate on radical principle of New Austrian Tunnelling Method,and then offer the corresponding order of Initial support to different rock. At last ,this paper Analysis Co-ordination role of shotcrete and rock bolt from aspect that rock becomes Bearing structure .3. According to the information gained at the site test ,the stability of the Jiu Ling small spacing tunnel's ground-support system is analyzed and estimated by results that Physical Measurement value compare with Physical allowed value.The results show that tunnel rock is stable and Support is effective.4. In this paper, plane computation module of small spacing tunnels is built according to practical project.The paper give a description of numerical simulation of small spacing tunnels cutting and timbering,and the paper analyzes small spacing tunnels into its constituent parts, which include displacement field,stress field,preliminary bracing of shotcrete and axial force of roofbolt.The results show that Deformation concentrated in the vault and the arch foot and the most obvious change in the dome, arched back and arch foot when tunnel is under construction.So we are monitoring According to the situation of excavation. The greatest moment value of the shotcrete and the largest axis force of roofbolt is in the tunnel arch foot,after completion of the initial support, inverted arch and the second support Should be completed so that it improves their stress and deformation and maintains the stability of the tunnel.5.According to the 3D FEM numerical simulation modeling by MIDAS GTS, this paper analyzes the surrounding rock stress, convergence of tunnel inner support bearing, establish and the justification of the construction.perimeter,the safety and the justification of the construction.Ultilizing numerical calculation solve rock-soil engineering is principal basis of engineering design and stability analysis for constructing. But owing to lots of indeterminate underground, to ensure the safety of tunnel construction and application, information back coupling in excution must be emphasized. And, utilize the information adjust the tunnel constructing.