Full-scale experimental investigation on progressive failure characteristics of shield segmental lining connected through segmental joints containing ductile-iron joint panels

A full-scale experiment was conducted for a deep-buried drainage shield tunnel to be built in Shanghai, focusing on the evolution of mechanical properties and failure process of the segmental lining connected through segmental joints containing ductile-iron joint panels, during the changing process of the inner water pressure and lateral earth pressure. The test results indicate that the damage characteristics of the shield lining are the waterproof failure of the segmental and ring joints, and the concrete cracking failure in the lining. Being different from the shield lining without ductile-iron joint panels, the concrete cracks mainly exist around the hand holes of segmental joints. For these kinds of shield tunnel linings containing ductile-iron joint panels, local damage of concrete cracking is prone to occur around the hand holes of segmental joints because of the anchor bars of the joint panels distributed on both sides of the hand holes, and it has a significant effect on the lining deformation. In the design of shield linings, effective structural adjustment methods should be adopted to solve this local concrete failure problem.

Automated summary

A full-scale experiment was conducted to study the mechanical properties and failure process of a deep-buried drainage shield tunnel in Shanghai. The experiment focused on the segmental lining connected through segmental joints containing ductile-iron joint panels. The test results revealed that the damage characteristics of the shield lining include waterproof failure of the joint panels and concrete cracking in the lining.