矩形顶管隧道F型承插接头剪切破坏机制

Shear Failure Mechanism of F-type Socket-and-Spigot Joint in Rectangular Pipe Jacking Tunnels

  • 摘要: 接头是矩形顶管隧道最薄弱的环节,对地基的不均匀沉降极为敏感,极易发生管节间的剪切错台变形。以 F型承插接头为研究对象,采用室内试验和 ABAQUS 有限元进行分析,归纳宏观破坏现象,得到了接头剪切变形机理,建立隧道变形控制标准。结果表明,顶管隧道剪切破坏特征分为缝隙闭合、抗剪强化、屈服破坏3个阶段,第二阶段剪切刚度最大;发生剪切破坏时,钢套环和混凝土在倒角位置易产生应力集中;适当添加纵向连接件可以提高柔性接头稳定性和剪切刚度;错台量达 12 mm 时,钢套环开始屈服,错台量为 27 mm 时钢套环开始发生塑性破坏。

     

    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.

     

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