关键词: 矩形顶管, 浅覆土施工, 基桩变形, 桩顶水平位移, 数值模拟

Abstract: To investigate the influence of horizontal deformation of foundation pile adjacent to viaduct caused by soil squeezing effect of pipe jacking construction, a case study is conducted on the entrance and exit section of No.1 metro on Qingshi road in Wuxi, China. Furthermore, the Midas GTS software is used to simulate the construction process of rectangular pipe jacking under the condition of shallowburied soil, and the horizontal deformation of foundation piles under various jacking distance, clear space between the foundation pile and the tunnel, jacking pressure of the excavation face, and friction between pipe joint and soil is calculated. The results reveal the following: (1) The adjacent piles will deform along the jacking direction and vertical jacking direction during the jacking construction of rectangular pipe jacking, and the deformation is mainly along the jacking direction. (2) The influence range of pile jacking construction under the condition of shallowburied soil is about 〖WT〗4D 〖WT５《TNR》〗outside the tunnel 〖WT〗(D 〖WT５《TNR》〗is the long side size of rectangular pipe jacking), and the horizontal deformation of pile increases with a decrease in clear space; when the clear space is less than 〖WT〗2D, 〖WT５《TNR》〗the horizontal deformation of the pile increases nonlinearly and rapidly. (3) The friction between the pipe joint and the soil has a greater impact on the foundation pile than jacking pressure of the excavation face, and the increase of the horizontal displacement can be divided into two stages, i.e., linear and nonlinear growth.

Key words: rectangular pipe jacking, tunneling under shallowburied soil, foundation pile deformation, pile top horizontal displacement, numerical simulation