Abstract: To explore the prediction method for long-term waterproof performance of sealing gaskets, the previous methods for predicting and fitting the performance of sealing gaskets in shield tunnels, as well as the aging test methods and results are summarized. On the basis of previous research, the aging test temperature is controlled within 90 ℃ and the aging duration is controlled within 168 h. The thermal oxygen aging test of dumbbell type I ethylene propylene diene monomer(EPDM) is conducted, the variation patterns of the elongation at break, tensile strength, and permanent deformation rate at break of EPDM are analyzed, and a chemical analysis is provided. According to the experimental results, the attenuation of EPDM elongation at break and permanent deformation at break is one of the reasons for the decrease in the waterproof performance of EPDM sealing gaskets. The tensile strength of EPDM has a small impact on the waterproof performance of EPDM sealing gaskets, and predicting the long-term waterproof performance of sealing gaskets using a certain index′s attenuation pattern is not reliable. The kinetic curve straightness method based on the Arrhenius equation predicts that the attenuation coefficient of EPDM elongation at break after 100 years is 37%.

Key words: shield tunnel, ethylene propylene diene monomer sealing gasket, thermal oxygen aging, waterproof performance