Research on the Joint Waterproofing of Precast Segmental Tunnel Linings in Water-Rich Stratum: Fid-Bau Portal

Research on the Joint Waterproofing of Precast Segmental Tunnel Linings in Water-Rich Stratum

Kong, Xiangxun / Luo, Yonghui / Wang, Shaojun

In the subway tunnels constructed by shields in the rich water area, the junction of the ring segments is a key issue to be solved in the project. In this paper, the waterproof performance of subway shield tunnel joints under different load conditions is studied. Through numerical simulation, unidirectional compression assembly force simulation and bidirectional extrusion simulation for M1 and M2 sections were carried out and then compared with the test data. In addition, according to the M1 section, the section form of the gasket was further improved to obtain better waterproof performance. The results show that in the absence of test conditions, the average contact stress on the surface of the EPDM gasket is used to characterize the waterproof performance of the gasket with safety and reliability. The variation rule of average contact stress with compression displacement is summarized, and the reliability evaluation standard of gasket section form during shield lining construction and operation is improved. Finally, according to the aging characteristics of the rubber material of the gasket, the waterproof performance of the gasket at the connection of the shield segment of an actual subway project is predicted during the expected service life.