Analysis of and Treatment Technologies for a Piping Accident in the Deep Foundation Pit of a Shield Tunnel
(1 CCCC Second Harbor Engineering Company Co. Ltd., Wuhan 430040; 2 The 3rd Engineering Company of CCCC Second Harbor Engineering Company Co. Ltd., Zhenjiang 212018)
Abstract:
Piping in deep foundation pits as a result of unsuitable dewatering or improper construction of an enclosing structure happens occasionally and severely affects the safety of construction.This can even lead to the foundation pit being out of service and can endanger the surroundings if such an accident is not treated quickly and properly, causing a great loss. Using the construction of a shield shaft on the south bank of line N in the Nanjing Weisan Road river-crossing tunnel as an example, and based on theoretical calculations and field surveys, the cause of a piping accident that occurred during foundation pit construction is analyzed and a comparison is made between the conventional treatment technologies for piping accidents in foundation pits.The selected final treatment measures include grouting and water blocking assisted by a high-pressure jet-grouted pile, which successfully resolved the problem and ensured smooth construction.
.Analysis of and Treatment Technologies for a Piping Accident in the Deep Foundation Pit of a Shield Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(4): 184-189