Study On Large Deformation And Control Technology Of High Ground Stress In Tian Ping Tunnel

When deep tunnel through soft rock and fault zones, generally in a large deformation under high stress conditions and rich water. This kind of tunnel rock deformation is large, and the displacement speed is also great, generally can reach tens of centimeters to several meters,if you do not support or support improper, the convergence of the final trend is that the tunnel will be completely sealed, if occurred in the permanent lining before building, often expressed as the initial support serious rupture, distortion, extrusion surface intrusion limit. This large deformation of great harm, seriously affecting the construction period or line normal operation,and the high cost of remediation.Based on the engineering background of the inclined shaft area of Tianping tunnel in Yuqian railway, taking the method of indoor experiment, theoretical analysis, numerical simulation and field monitoring, according to the strata and engineering characteristics of Tianping tunnel, the large deformation mechanism and its influencing factors of the surrounding rock of carbonaceous rock tunnel under construction disturbance are systematically analyzed, Combined tunnel - analysis of the relationship between "support surrounding rock," the large deformation of soft rock tunnel control method is proposed to form the key technology of large deformation of tunnel excavation and support.The results of the application in the Tianping tunnel can be done before the advance, in place, on the basis of the forecast by monitoring the data analysis and adjustment of the support parameters to ensure that the Tianping tunnel soft rock tunnel safety construction, and the same Under the complicated conditions of underground engineering research and support to provide reference and reference, the paper made the main results are as follows:(1) The geostress testing method of tunnel is compared and analyzed, and the guiding method of ground stress is put forward. Combined with the results of geostress test, the reasonable excavation method and supporting parameters are put forward, which solves the problems such as the early excavation of high ground stress and the deformation of the bottom plate. Promote the application laid the foundation.(2) Analyze the mechanical properties of soft rock under the high ground stress environment, and combine the scheme to establish the theoretical model. The numerical simulation analysis of the data into the theoretical model is carried out. The preliminary analysis conclusion is obtained, and then the actual situation is compared and analyzed,proposed a reasonable excavation methods and support parameters optimization program for the safe and rapid construction to provide technical support and theoretical basis.(3) In view of the high ground stress soft rock tunnel engineering, combined with the construction mechanics behavior analysis, developed the rapid construction principles and the overall program, that is "advanced support, initial support strengthening, reasonable deformation, first relaxing then resisting, first soft then rigid, timely closed, bottom Strengthening and structure improving, and geological forecast". With the first guide and other auxiliary program to solve the tunnel construction problems, the safety control standards were put forward.