Shear performance of wedge‐type shield tunnel segment joints reinforced with steel box girders

After structural damage occurred in the shield tunnels, reinforcements are required. The mechanical behavior of the inclined joints in wedge‐type segments is more complex owing to their special configuration. This study investigated the shear performance of wedge‐type joints under dislocation‐induced failure and proposed a steel box girder reinforcement method to repair damaged joints. The results show that the inclined distribution of joints had a significant influence on the mechanical behavior of the wedge‐type segment. The growth rate of radial displacement on the wide side was greater than that on the narrow side. After the damaged joints were reinforced with steel box girders, the shear stiffness of the joints was significantly improved. As the dislocation continued to increase, bonding failure first occurred in the joint regions. The adhesive bolts at the joint edges restrained the propagation of bonding failure. The distance between these adhesive bolts and the joints had a significant influence on the mechanical response of the steel box girders. Reducing the distance can effectively restrain the development of joint dislocation. Joint dislocation also intensified the force demand on these adhesive bolts, eventually causing damage to the concrete in this region, which in turn led to the deterioration of reinforcement.