Ground Surface Deformation Caused by Pipe Jacking Construction in a Soft Soil Area: An Experiment-Based Study

Abstract

Soft soil has the characteristics of high compressibility, large void ratio, and strong structure. Therefore, it is more likely to cause surface subsidence or even surface cracking and collapse when laying oil and gas pipelines in soft soil areas through the pipe jacking method. In this study, test soil was pressurized using a flexible loading bladder, and variable formation losses brought on by pipe jacking were mimicked by varying the loading bladder’s water injection level. The surface deformation brought on by pipe jacking construction is related to the four parameters of stratum loss rate, overburden load, soil disturbance, soil tension fissures, and horizontal deformation. The findings demonstrate that the surface deformation brought on by the excavation gradually reduces and starts to stabilize after the thickness of the overlying soil layer on the pipe jacking surpasses 1.5 times the diameter of the pipe jacking. The constructed settling tank is broader the deeper the jacking pipe is submerged. Further ground surface settling will be exacerbated by the weight above the jacking pipe. The maximum ground surface deformation value will decrease with an increase in the overlying load when the overlying load is high (0.018 MPa).