Research on Circumferential Deformation of Metro Shield Tunnel Based on FBG Monitoring Technology
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 6
Abstract
Objective FBG (fiber bragg grating) monitoring technology features fast dynamic response, strong anti-interference, high precision and strong durability, and can realize long-distance real-time monitoring. The feedback circumferential deformation monitoring data from FBG is of great significance to the parameter adjustment in the process of shield tunneling. Therefore, it is necessary to conduct an in-depth research on the circumferential deformation law of the segments based on FBG technology. Method With a metro tunnel project as the example, the fiber optic sensors are used for real-time monitoring of the segments during metro tunnel construction. Through analysis of the monitoring data, the changing law of the circumferential strain in the segment construction environment is studied, and the correlation between the relative convergence displacement and the shield tunneling parameters is analyzed. Result & Conclusion The monitoring data indicates that the circumferential deformation mainly occurs within one week after the installation of the tunnel segments and within a 50 m range of the adjacent tunnel excavation. In condition of unfavorable stratum and small buried depth, the effect of the subsequent tunnel excavation on the convergence of the already constructed segments is about 50%. When the stratum is favorable and the buried depth is large, the effect of subsequent tunnel excavation on the above convergence is approximately 65% to 83%. The strain of the segments is affected significantly by the stratum and the adjacent tunnel construction under different buried depths. The segments in a shallow buried depth and poor soil stratum have large deformation, while those in the larger buried depth exhibit better constraint and unnoticeable deformation. There is a clear correlation between the relative convergence displacement and the shield tunneling parameters. The total thrust of the subsequent shield tunneling is negatively correlated with the relative convergence displacement of the previously constructed segments, while the excavation speed of the subsequent shield tunneling is positively correlated with the above relative convergence displacement. The real-time monitoring data obtained through FBG monitoring technology can serve as a basis for adjusting the shield tunneling parameters.
Authors and Affiliations
Xingyun DAI, Baogang MU, Jin TAO
Keywords
Related Articles
- EP ID EP737757
- DOI 10.16037/j.1007-869x.2024.06.028
- Views 40
- Downloads 0
Impact of Small Clearance Bored Pile Construction under Rail Transit Bridges in Soft Soil Area
Objective The impact of small clearance construction between bored piles and piers of operational rail transit bridges in China′s coastal soft soil areas is becoming a bottleneck factor restricting urban rail transit pla...
Metro Train Passenger Evacuation Model Based on NFPA 130:2023 Standard for Fixed Guideway Transit and Passenger RailSystems
［Objective］ Due to the relatively confined space and high passenger capacity of metro trains, fire safety and life protection are attracting significant attentions in the public transportation industry. To evaluate the...
Simulation Analysis of Segment Joint Deformation and Waterproof Performance under High-speed Train Vibration in Large-diameter Shield Tunnel
Objective To prevent water leakage issues in large-diameter shield tunnel, ensure high-speed train operational safety and normal tunnel functionality, it is necessary to carry out analysis and research on tunnel segment...
Application of New Electricity Saving Technology in Urban Rail Transit Depot
[Objective] The electricity consumption in vehicle depot accounts for a large proportion of the total in urban rail transit. In order to reduce the depot electricity consumption, it is necessary to do research on the app...
Coupling Characteristics of Operational Safety Risks in Urban Rail Transit
Objective Urban rail transit system is a complex integrated system involving people, machine, environment, and management, with its operational risks existing not independently or statically. Understanding the dynamic co...