Study On Deformation Control Technology Of High Stress Soft Rock Large Deformation Tunnel

With the development of the infrastructure,the corresponding problems in the tunnel construction technology are also in the research and development.Based on Ling Da Na tunnel in Sichuan to Tibet railway which is the national major new project.,This paper briefly introduces the project profile and construction issues.Through the numerical simulation of the construction scheme and field observation analysis,this paper analyzes the engineering geological characteristics of high stress soft rock tunnel and the deformation characteristics of surrounding rock,and explores its mechanism of large deformation mechanics.Combining the above researching with the supporting mechanism of numerical simulation of a variety of supporting schemes,this paper determine the best supporting schemes for different levels of surrounding rock deformation,and connecting with the actual tunnel construction,puts forward the control of large deformation of high stress soft rock tunnel method in detail,finally,through the study of monitoring measurement data in the test section of the site,to demonstrate the effectiveness of supporting schemes.The main results of this study are as follows:(1)the engineering geological characteristics and mechanical properties of the high stress soft rock tunnel are systematically discussed,and the characteristics of the large deformation of tunnel soft rock and its influencing factors and supporting principles are discussed.(2)This paper briefly expounds the basic principles and characteristics of tunnel construction.Using finite element software MIDAS GTS,to make up to take finite element numerical simulation for tunnel excavation support scheme,combined with the tunnel construction site monitoring measurement data,explore its deformation and failure characteristics of high stress soft rock tunnel and the mechanism of large deformation(3)Through to the high in-situ stress soft rock tunnel deformation instability mechanism is analyzed combined with engineering practice,in view of the level of soft rock deformation,slight deformation,the medium deformation,severe deformation,respectively,puts forward the preliminary design supporting system,and numerical simulation analysis,select the best supporting scheme is applicable to the scene,and detailed method and explains its excavation support scheme.(4)Finally,the excavation support scheme proposed by the authors in relying on the tunnels for field test and verify its supporting effect,conclusion is made to take the tunnel construction chooses deformation control of the technical scheme is reasonable,but also for railway high stress soft rock tunnel supporting design and construction to provide the reference.