Abstract:

The connecting tunnel of YoufangqiaoZhonghecun section of line 2 of Nanjing Metro is 20m long. Freezing is executed from both ends of the connecting tunnel in the construction. The thickness of the freezing walls, the layout of the freezing boreholes, the design of the freezing systems, the execution of the freezing and the installation and operation of the freezing stations are discussed. The temperatures of the feeding and returning brines, the temperatures of the freezing curtains and the ground surface deformation are monitored to summarize their variation rules. The freezing effect and the risk evaluation are analyzed.

Key words: shieldbored tunnel, connecting tunnel, freezing from both ends, freezing consolidation, freezing borehole