Deformation Rules and Failure Mechanisms of Shield Tunnel Lining with Constant Buried Depth Ratio Under Overload Condition

The maintenance of shield tunnel linings is critical for the successful operation of super-large-diameter shield tunnels. In this study, the finite element analysis method is used to systematically investigate the deformation behavior of shield tunnel linings with varying diameters based on ABAQUS. Key parameters such as crown displacement, tensile and compressive strain zones, bolt stress and strain, as well as the deformation and internal force distribution around the lining, are comprehensively analyzed. Additionally, the development of cracks in the tensile zones is examined for comparative analysis. The findings reveal that large-diameter linings exhibit a more rapid increase in convergence deformation, while fewer plastic hinges form before reaching maximum strength. Furthermore, these larger linings are more susceptible to brittle failure and geometric instability compared to smaller-diameter counterparts. The results of this study provide significant theoretical insights for the design, construction, and operation of large-diameter shield tunnel linings, offering valuable references for similar engineering applications.