Abstract: The aging of EPDM sealing gasket for shield tunnel segment joints during operation will lead to stress relaxation and attenuation of waterproof performance. The current rubber aging model cannot evaluate the long-term stress relaxation of waterproof gasket under non-uniform compression. In this paper, a hyper-viscoelastic aging model of long-term stress relaxation of rubber at different temperatures and strain levels is established by theoretical method, and numerical implementation is carried out in the ABAQUS. The aging test and waterproof test of sealing gasket are further carried out, showing that the waterproof performance of the waterproof gasket aging for 3 days under the condition that joint opening 6 mm, no dislocation and 70 °C is about 27% of the unaged gasket.The results obtained from numerical simulations based on the aging model align well with the stress relaxation test results of sealing gaskets and the waterproof performance test results of aged sealing gaskets, verifying the applicability of the super-viscoelastic aging model in evaluating the long-term mechanical and waterproof performance of sealing gasket components in shield tunnel segment joints. The evaluation results of the aging model after numerical implementation indicate that the sealing gasket, after being aged for 3 days under the condition of 70℃ and a joint opening of 5 mm, corresponds to a service life of 91 years under the condition of 25℃ and a joint opening of 5 mm. Finally, the long-term waterproof performance of gasket in Nanhu Tunnel is analyzed, showing that the waterproof performance can reach 0.8 MPa after 100 years of service in 25 ℃ when joint opening is smaller than 7 mm, which meets design requirement.

Key words: shield tunnel, waterproof sealing gasket, aging, stress relaxation, hyper-viscoelastic aging model