Monitoring-Assisted Large-Diameter Shield Tunneling Control in Soft Ground: A Case Study of Bund Tunnel Project

Tunnel projects usually hold risks especially in populated and complex urban environment. Onsite monitoring can obtain useful environment information and provides dynamic feedbacks. This paper takes the Shanghai Bund Tunnel project as a case study and describes how onsite monitoring assists shield tunneling. It is the first application of super-large diameter (14.27 m) earth pressure balanced (EPB) shield in China. In order to control tunneling risk, dense onsite monitoring has been taken and both electrical gauges and fiber Bragg grating (FBG) sensors are applied in data acquisition. The working principle and installation of the FBG sensor, as well as the data analysis are specified. The dense monitoring significantly mitigates the risks and contribute to a successful finishing of the project.