Study On The Construction Technology Of TBM Launching Section In Chongqing

This paper take the TBM test section of Chongqing Metro Line 6 as background, where TBM is first used in construction in the city and therefore, many problems have to be solved. In the construction of the launching section of tunnel excavated with TBM, there is always a problem that rock strength can't meet the pressure of gripper shoes. This is what this paper focus on.TBM(tunnel boring machine) is mainly used in construction of mountain tunnels. This paper analyzed designing and construction of the launching section of tunnel under the circumstances of Chongqing Metro rock. Because of the project's uniqueness and high cost, theoretical and numerical analysis for construction technology was firstly made from the perspective of parameters, in order to get reasonable construction measures.This paper verified and compared the designing of supporting and pre-reinforcement with help of the finite element software ANSYS, and get reasonable pressure of gripper shoes and pre-reinforcement approach when TBM get through broken rock, which can meet the time limit of construction. Firstly, a reasonable pressure of the gripper shoes was got by analysis the force and deformation of rock and lining in prepared and starting hole; then, a reasonable rock reinforcement approaches was got by comparing rock parameters. Focusing on the force and deformation of rock under the pressure of gripper shoes made the result more clear.Throughout the whole paper, a proper and time-meeting pressure of gripper shoes was got by comparing the force and deformation of rock and lining in prepared and starting hole. When TBM meet broken rock, a reasonable rock reinforcement approaches was also got by comparing rock parameters. All these approaches and conclusion were summarized.