On Parameter Optimization for a Slurry Shield Approaching Construction under Existing Subway Tunnels in Water-Rich Pebble and Mudstone Composite Stratum
(1 College of Architecture and Communications, Liaoning Technical University, Fuxin 123009; 2 School of Civil Engineering, Liaoning Technical University, Fuxin 123009;3 The Fifth Construction Ltd. of China Tiesiju Civil Engineering Group, Jiujiang 332000)
Abstract:
Due to the rapid development of urban rail transit, the situation where new tunnels passing under exist? ing tunnels at a close distance is inevitable, and the risk control is mainly achieved by controlling the driving parameters. Based on the running tunnel section between Xiuling Road Station and Mingxiu Road Station of Nanning Metro Line 5, this paper analyzes and optimizes the driving parameters through laboratory similarity tests, and establishes a folded wedge model being applicable to the upper-soft and lower-hard composite stratum, finally it conducts a comparative study regarding the driving parameters of the slurry balance shield in the full-face mudstone strata as well as in the pebble and mudstone composite strata. The study results show that it is technically feasible to optimize the driving parameters by using the control variable method through laboratory similarity tests; compared with conventional models, the hypothesis that the failure surface is approximately assumed as a folded line, is more suitable for the deformation and failure modes of the upper-soft and lower-hard composite stratum; the driving parameters fluctuate in a wide range when the slurry shield in full-face mudstone strata, with the cutterhead torque and total thrust being particularly pronounced.
SONG Yang1 WANG Weiyi2 DU Chunsheng3
.On Parameter Optimization for a Slurry Shield Approaching Construction under Existing Subway Tunnels in Water-Rich Pebble and Mudstone Composite Stratum[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 85-95