Analysis on Ground Surface Heaving ahead of Cutting Face Caused by Largesection Rectangular Pipe Jacking in Soft Soil Layer
(1 School of Civil Engineering, Guangxi University, Nanning 530004; 2 Key Laboratory of Engineering Disaster Prevention and Structural Safety, Ministry of Education, Nanning 530004; 3 China Railway No.10 Engineering Group Co., Ltd., Jinan 250101)
Abstract：
The large ground surface heaving in front of the cutting face during the pipe jacking is studied on the ba? sis of a large-section rectangular jacking pipe works at the entrance/exit of a subway station in Ningbo. The monitored data of ground surface deformation in the whole pipe jacking process are analyzed in combination with the jacking situation on the site. Moreover, PLAXIS finite element software is used to simulate pipe jacking under different jacking forces and without soil reinforcement, and the simulated results are compared and analyzed with the monitored data. The analysis results show that the large ground surface heaving can be generated due to excessive jacking force, and vice versa; the jet grouting piles used for reinforcing the entrances/exits area adjacent to the structure have no desirable effect, and it could cause the ground surface heaving at the beginning of jacking. The ground surface heaves rapidly when the pipe jacking and extruding in the soft soil layer, but subsides slowly after the jacking face passing. So, special attention should be paid during the construction.
2021, Vol. 58 