关键词: 大直径盾构, 越江隧道, 防水密封垫, 角部构造

Abstract: Solid is usually adopted for corner structures of shield tunnel waterproof gaskets. In the construction and assembly of a largediameter shield tunnel crossing a river, the corner of the gasket is easily extruded. This can easily lead to a concentration of stress or even fracturing of the concrete in the corner segment. Accordingly, to provide an experimental basis for the optimization of the design of the structure of a waterproof sealing gasket corner, a case study is conducted on a waterproof engineering project that involves the creation of a largediameter shield tunnel within a soft stratum. The project studied is the Xiangjisi Road west extension project in Hangzhou. This project is used to study how different openings in the gasket affect the compression force in the gasket during the process of compression. A total of five sealing gasket corner configurations with different opening lengths and opening radii are designed. Closure compression tests are carried out, and the test results are compared with those for a standard sealing gasket. The experimental results show that, for a scheme consisting of two holes with a radius of 8 mm in the corner of the gasket, the closure compression force for the hole in the center is 76.10 kN/m, which is 38.3% less than for a scheme with no holes. This meets the requirements of the assembly. The contact stress at the corner is found to be 0.89 MPa, which is a reduction of 24% compared with the situation where there is no opening. It is concluded that the closure compression force can be reduced while maintaining a large contact stress. 

Key words: largediameter shield, rivercrossing tunnel, waterproof gasket, corner structure