Numerical Simulation Analysis of Supporting Stability of Cast-in-place Piles in Pipe Jacking

Abstract

Combined with the support excavation and pipe jacking construction of the pipe jacking working well in a section of Zhenjiang sponge city plan construction, the three-dimensional numerical analysis model was established by MIDAS-GTS, and the deformation of the supporting structure at each construction stage was analyzed. The conclusions are as follows: when the three-dimensional numerical analysis model is established, the deformation of the beam element is closer to the real situation than that of the plate element beam element; in the process of pipe jacking construction, the displacement of the supporting structure is opposite to that of the jacking direction after the Jack loads, and the displacement trend changes linearly with the magnitude of the Jack force. in the process of pipe jacking construction, the maximum displacement of the supporting pile occurs at the break of the supporting pile at the exit of the pipe jacking machine. the deformation of the supporting pile can be effectively reduced by strengthening the soil in a certain range of the opening of the pipe jacking. Through the simulation analysis of excavation support and subsequent pipe-jacking construction with concrete cast-in-place pile, the results can provide a reference for the design of supporting structure and the control of surface subsidence and deformation during construction.