Shear Failure Mechanism of F-type Socket-and-Spigot Joint in Rectangular Pipe Jacking Tunnels
(1. School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou 014010; 2. Academician Workstation of Mine Safety and Underground Engineering, Inner Mongolia University of Science and Technology, Baotou 014010; 3. Engineering Research Center of Urban Underground Engineering at Universities of Inner Mongolia Autonomous Region, Inner Mongolia University of Science and Technology, Baotou 014010)
Abstract：
The joint is the weakest link of the rectangular pipe jacking tunnel, which is very sensitive to the uneven settlement of the foundation, and is prone to shear dislocation and deformation between pipe joints. Taking the Ftype socket-and-spigot joint as the research object, the indoor test and ABAQUS finite element were used to analyze the macroscopic failure phenomenon, the shear deformation mechanism of the joint was obtained, and the tunnel deformation control standard was established. The results show that the shear failure characteristics of the pipe jacking tunnel are divided into three stages: gap closure, shear strengthening and yield failure, and the shear stiffness in the second stage is the largest; when shear failure occurs, the steel ferrule and concrete are prone to stress concentration at the chamfered position; proper addition of longitudinal connectors can improve the stability and shear stiffness of flexible joints; the steel ferrule begins to yield at a staggered volume of 12 mm, and the plastic failure begins to occur when the staggered volume is 27 mm.
2023, Vol. 60 