Monitoring and Analysis of System Transition in the Closure Joint Using the Segment‐jacking Method

Abstract The closure joint using the segment‐jacking method adopted in the Dalian Bay Tunnel marks the inaugural application of a novel closure joint configuration in China's immersed tube tunnel industry. The structural system transition phase of this method poses notable safety risks and is pivotal to the success of the segment‐jacking method. To tackle challenges such as the difficulty in inspecting the installation quality of steel braces and the heightened construction risks associated with the system transition process, this paper builds upon an analysis of the mechanical forces involved during the system transition. By establishing a monitoring system and leveraging preload tests to assess the load‐bearing capacity of steel braces, this study pools data on the rebound of waterstop seals and the deformation of steel braces during the structural system transition of the closure joint using the segment‐jacking method. This approach ensures that the structural safety of the transition process is controllable, thereby paving the way for the broader adoption of the closure joint technology in the segment‐jacking method.