Mechanical behavior and waterproof performance of longitudinal section of tunnel segment joint gasket

Abstract

In the construction stage, due to construction errors and longitudinal differential settlement during tunnel operation, the amount of dislocation and opening at the segment joint increases, increasing the likelihood of water leakage. Therefore, it is necessary to conduct an in-depth study on the influence of the amount of dislocation and opening at the segment joints on the contact stress of the longitudinal section. Firstly, through theoretical analysis, this paper deduces that the waterproof performance of the gasket depends not only on its own contact area, linear compression stiffness, and Poisson’s ratio but also on the height of the segment joint specimen and the amount of joint opening caused by the sinking offset angle. Then, the effects of different openings and dislocations at the segment joints on the contact stress of the segment gasket section were compared using numerical simulation and model experiments. Through numerical simulation, it is found that the dislocation has a greater influence on the longitudinal left section. The average contact stress at 16 mm is 28.3% lower than that at 4 mm, and the influence of the opening amount on the sealing gasket section is greater than that of the dislocation. Combined with the test results, it is also shown that the influence of the opening amount of the waterproof performance at the segment joint is greater than that of the dislocation, and the waterproof rate of the segment gasket section joint is greater than 40% under the modified working condition.