Abstract:

During the construction of the running tunnel from Qiushui Square Station to Zhongshanxilu Station on Line 1 of Nanchang Metro, the slurry shield crosses Ganjiang river under shallow permeable cover, which may result in the instability of the excavation face, clogging of the cutter head and difficulty in controlling the shield attitude. In the paper, the control of the stability of the excavation face is analyzed in terms of selection of the slurry parameters, calculation of the water pressure at the cutting edge and control of the shield boring parameters; the clogging of the cutter head is analyzed and it is proposed that the parameters of the slurry should be strictly controlled so as to ensure smooth shield boring; the boring parameters of the first 100 rings (from Ring No. 165 to Ring No. 265) of NFM07 shield and S367 shield are analyzed, and parameters are proposed for slurry shield boring under shallow permeable cover.

Key words: Nanchang Metro, rivercrossing tunnel, slurry shield, shallow permeable cover, excavation face stability, clogging