Emulation Of Excavating Process And Stability Analysis Of Surrornding Rock For Gangkou Bi-arch Tunnel

In the last few years, with the development of highway, the number of tunnel has evidently increased. The Bi-arch tunnels are new type of great span tunnel modality advanced with the rapid development of highway constuct in our country. Bi-arch tunnel, which have the advantage of smooth line type,higher use factor of space, lower land occupancy, and been convenient for the tunnel to connect with the way out of the tunnel, have been adopted in the highway proj ect increasingly.In this paper ,on the basis of the Gangkou Bi-arch tunnel practice of JingDezhen - WuYuan - HuangShan highway, take the highway tunnel adjacent formation stability appraisal as the master line, take protects the surrounding rock from to be steady and the instruction construction as the goal, guarantees the surrounding rock stability to achieve the highway project to the tunnel surrounding rock specific request for safe. Using the method of qualitative and quantitative evaluation of the overall evaluation and combine partial evaluation , To carry out a systematic study of the stability of surrounding rock. In this paper ,Start with geological engineering factors affecting the stability of the surrounding rock,analysis and discussion for the mechanism of surrounding rock deformation and failure. On the basis of Gangkou Bi-arch tunnel ,Analysis the change with geological condition,surrounding rock of stess and strain and the stability of the surrounding rock . Come to :The GangKou Bi-arch tunnels generally more stable. With the site monitoring data,this paper analysed comprehensively stress and strain of the surrounding rock and stability of the arched tunnel with joint, fracture developed,weathered rocks of metamorphic, The principle and characteristic of the NATM monitoring are summarized in the paper too.Based on the results of test, monitoring and numerical analysis with construction mechanical response of the tunnel,analysis of rock deformation characteristics of the tunnel. Based on the test ,monitoring and preliminary analysis,founding a model of geological construction.Using FLAC3D software for finite element numerical simulation of the construction process. By "one guide holes" program and "the three holes" CoMParative analysis simulation program for construction, come to "one guide holes" program is more suited to the preliminary findings of the Gangkou arched tunnel.Combined with monitoring data,as coMPared with"one guide holes "the numerical simulation results,during the course of the construction and operation of the tunnel on the overall stability analysis. the relevant engineering measures are suggested.Through the stability of the surrounding rock above-mentioned, Come to :the GangKou Bi-arch tunnel generally more stable,but the stability of surrounding rock of tunnel opening generally poor stable; Through the construction process simulation,guided "one guide holes" program is better.