Abstract:

Open TBMs are used in the construction of Wulidian StationShanyanggou Reservoir Station section of the first phase of No. 6 line of Chongqing rail transit project, which is the first time in China that open TBMs have been used in the construction of rail transit works. The engineering practice of the tunneling of the trial section by open TBMs shows that the tunneling has such problems as the primary support being too strong, the secondary lining being difficult to be installed, and the construction schedule being difficult to be controlled. Countermeasures, including optimizing the design of the primary support based on “dynamic design and dynamic construction” concept, adopting “synchronous ling” and optimizing open TBM tunneling plan, are proposed. In the end, the open TBMs have achieved successful driving in the trial section, which verifies the feasibility of open TBMs in the construction of underground tunnels of Chongqing rail transit works. 

Key words: Chongqing rail transit works, open TBM, primary support, secondary lining, monitoring