ABSTRACT
Circumferential joint dislocation of shield tunnel segments frequently occurs in soft soil environments due to external disturbances, posing a threat to the operational safety of the tunnel. Concave and convex tenons are commonly used to enhance the shear stiffness of circumferential joints. This paper introduces an innovative joint design that incorporates anti-crack meshes and rebars to effectively prevent concrete damage in the tenons and improve the shear resistance of circumferential joints. A comparative analysis was conducted on concrete damage under dislocation conditions for concave tenons reinforced with spiral rebars versus those reinforced with crossed rebars and anti-crack meshes. The results demonstrate that the novel joint, which combines crossed rebars, spiral rebars, and anti-crack meshes, significantly improves shear stiffness. However, this design also increases principal stress on the rebars while reducing concrete damage to the tenons. The innovative joint transfers part of the load-bearing function from the concrete to the rebars, thereby mitigating concrete damage. Compared to the original design, the reinforcement scheme notably limits concrete damage of the convex tenon, with a maximum reduction in severe damage volume reaching 72.26%. Furthermore, reducing damage to both the concave and convex tenons during circumferential joint dislocation could help prevent water leakage in tunnel segments.
