Research on the design and key technologies for the health monitoring of the Chongtai Yangtze River Tunnel

Long-distance railway shield tunnels face prominent difficulties in the structural health monitoring (SHM) design and implementation, with rare relevant engineering cases for reference. Targeting this challenge, this study takes the Chongtai Yangtze River tunnel on the Shanghai-Nanjing section of the Shanghai-Chongqing-Chengdu High-speed railway as the engineering prototype. Multiple research methodologies, namely technical investigation, theoretical analysis, multidisciplinary integrated design and field testing combined with on-site validation, were employed in this work to establish the SHM system design scheme and develop matched installation and construction technologies. The SHM system is deployed to collect and analyze structural load and internal force data during construction. The results indicates that the proposed design and installation technologies feature favorable practicability and operability. The monitoring data are authentic and reliable, which can accurately reveal the mechanical response evolution of the tunnel during segment assembly and shield tail departure, exhibiting strong correlation with construction procedures.