Numerical and Experimental Investigation on Waterproof Performance of Novel Sealing Gasket for Bolt Holes in Shield Tunnel Segments

To enhance the waterproofing performance of segment bolt holes in shield tunnels and ensure they meet the synergistic waterproofing requirements of segment joint sealing systems, a novel sealing gasket installed at the joint interface of the segment bolt hole has been designed. Numerical analysis was employed for a parametric study of factors influencing the waterproofing performance of the new gasket. Additionally, experimental research was conducted to evaluate its waterproofing capabilities. The study’s findings indicate that the hardness, height, and width of the novel bolt hole waterproof gasket significantly influence both the closure compression force and waterproofing performance. In contrast, the inner diameter primarily affects the closure compression force with a minimal impact on waterproofing performance. Compared to traditional water-swellable gaskets used for segment bolt holes, the novel EPDM (Ethylene Propylene Diene Monomer) waterproof gasket is more effective in mitigating the effects of manufacturing defects. For double-gasket segment joint sealing systems where the waterproofing strength of the bolt hole is critical, the adoption of this novel bolt hole waterproof gasket can better satisfy the synergistic waterproofing requirements between the two sealing gaskets, thereby effectively improving the overall waterproofing capacity of the segment joint sealing system.