Performance of composite EPDM gaskets for underground structures: Experimental and numerical investigation

This study presents performance of composite ethylene propylene diene monomer (EPDM) gaskets for underground structures. The composite gasket is made from water-swelling rubber and polyurethane (WSRP) combined with EPDM. The hydro-mechanical behavior of the WSRP-EPDM gaskets was rigorously evaluated through a series of tests. Laboratory investigations comprised gasket-groove compression tests to derive load-displacement curves, alongside joint waterproofing tests conducted under 18 distinct operational scenarios involving varying joint openings and offsets. Compression behavior revealed three characteristic phases: linear growth, gradual growth, and significant growth. Experimental results established clear correlations between sealing performance and the investigated parameters. Finite element analysis (FEA) was employed to investigate stress distribution, displacement patterns, and contact stress characteristics within the gasket system. By integrating experimental data with FEA results, this study developed an empirical equation that quantitatively describes the relationship between average contact stress and the sealing performance of WSRP-EPDM gaskets. The findings provide valuable insights and actionable design guidelines for optimizing WSRP-EPDM gaskets in prefabricated underground infrastructure.