Stress Analysis of Large-diameter Undersea Shield Tunnel Lining Segments during Construction Process

Abstract

Objective To assess the engineering safety and reliability of undersea large-diameter shield tunnel structures, it is essential to analyze the stress on lining segments. Method Taking the lining segments of Dalian Railway Station-Suoyuwan South Station Interval undersea shield tunnel on Dalian Metro Line 5 as research object, MIDAS GTS finite element analysis software is used to model the shield tunnel structure and the surrounding rock mass. The stress on lining segments after a period of construction is obtained and comparatively analyzed with field monitoring and theoretical calculation data. Result & Conclusion The earth pressure on lining segments remains relatively stable as construction progresses. There are certain differences in earth pressure at different points on the same monitoring section, with the arch vault and bottom experiencing higher stress. Therefore, during both the construction and future operation periods of the tunnel, the arch vault and bottom should be areas of key focus and be reinforced through physical measures. The onsite monitoring and numerical simulation data indicate that the internal forces on lining segments are quite similar. Under certain simplified conditions, the numerical model can quite realistically reflect the actual stress conditions of lining segments.

Keywords

• undersea tunnel
• large-diameter shield tunnel
• lining segment
• segment stress