Study on Assembly and Tensile Performance of Circumferential Anchor Joint for Shield Tunnel Considering Roughness and Size of Structure

Anchor joint is conducive to improving the automation level of the shield tunneling method, whose mechanical behavior is still not fully clear due to the complicated interaction among various structural components. In this paper, a refined FEM model is established and adopted to investigate the anchor joints’ assembly and tensile performance. The operation principles of the anchor joint are first introduced for better understanding. Then, a detailed description is presented for the developed refined FEM, including the material properties, structural features, and verification. After that, 76 working conditions in total are set, and an in-depth study is conducted to examine the influence of surface roughness, gap sizes, and strength grades on the assembly and tensile behavior of anchor joints both quantitatively and qualitatively. The results show that the surface roughness mainly influences the maximum assembly load and tensile capacity of anchor joints. The gap size obviously impacts both quantitative and qualitative assembly characteristics and tensile behavior for anchor joints, whose effect is more significant than the surface roughness. The strength grade has a different influence on the distinct mechanical behavior of anchor joints. There is a positive correlation between anchor joints’ assembly and tensile behavior. To satisfy the requirement of enough tensile capacity and reasonable assembly difficulty, a good solution should be to reach an appropriate balance between the assembly and tensile behavior of anchor joints.