Analysis Of Stability About Excavation And Support Of Tunnel

China is a mountainous country. With the rapid development of expressway constructionin China, tunnel engineering is increasing. Because of the complexity of the geologicalcondition and hydrogeological conditions in mountainous area, while tunnel constructiondevelop rapidly, the construction technology is also facing the increasingly serious challengesin many aspects. Especially in the tunnel construction in soft rock area, soft rock largedeformation m law research has become hot proble of soft rock tunnel construction. At thesame time, soft rock large deformation control is the key to the success of soft tunneltechnology. Due to the complexity of soft rock deformation characteristics, soft rockdeformation control technology still remains controversial and the exploration stage. In thisarticle，taking the soft rock tunnel as the project, the soft surrounding rock deformation lawand support parameters were systematically analyzed. The main work is as follows：On the basis of the previous research, the soft rock creep characteristics and the creepconstitutive model to describe creep features are reviewed.The deformation characteristicsand stress characteristics of soft rock tunnel were analyzed summaried in detail. Introducedtwo kinds of constitutive models of the soft rock tunnel commonly used in numerical analysis.Established the theoretic foundation for the analysis of soft rock tunnel(2)According to indoor test results of rock physical and mechanic parameters of thetunnel area rock, combined with the RMR rock mass classification standard, the rock mass areclassified and graded.By the score and Hoek-Brown method, the rock strength anddeformation parameters are estimated. The rock mechanics parameters of tunnel are gotten.(3)Establishing numerical analysis model, using Mohr-Coulomb criterion, applying theFLAC3D software, systemly analyzed and comparied the tunnel deformation and stresscharacteristics of soft rock tunnel of the two kind different excavation methods between thefull section excavation and CRD under different conditions, obtained the deformation law ofdifferent excavation and support conditions. Provides guidance for tunnel construction.(4)While completed the necessarily measured projects of tunnel, selecting two typicalcross section completed the site monitoring items of selecting measured projects. Bycomparing the monitoring results and simulation analysis results, verified the correctness ofthe numerical analysis theory and the rationality of construction method and supportingparameterns.