Waterproofing Performance of Shield-Driven Tunnel's Segment Joint under Ultra High Water Pressure

The key parameters for waterproofing ability of segment joint of shield-driven tunnel - such as waterproof rule of segment joint, water resistance of gasket, and the value of assembly force of ethylene-propylene-diene monomer (EPDM) rubber gasket - have always been the research focuses in this field. This paper studied these key parameters for Nanjing Weisan Road passing river tunnel project through the new high water pressure, automatic loading device. The test results indicated: (1) waterproofing ability and variation law of EPDM rubber gasket in `—'shaped test are quite different from those of `T' shaped test; (2) waterproofing ability of EPDM rubber gasket is largely related to its assembly force and average contact stress based on optimizing section form of gasket; and (3) hardness, section form and filling ratio of gasket have significant impacts on its waterproofing performance. Finally, based on the test results, this paper summarized significant rules and several beneficial conclusions for the design and analysis of segment joint waterproofing of shield-driven tunnel.