Abstract
Gushing water disasters pose a significant challenge to safe tunnel construction in coastal karst areas. Understanding the grouting plugging mechanism is crucial for effectively preventing and controlling gushing water in these regions. However, existing grouting plugging mechanisms primarily focus on non-expansive slurries and lack adequate guidance for self-expanding materials. To address this gap, this study first develops a theoretical model for Expanded Polyethylene Modified (EPEM) grouting plugging and derives the plugging criterion formula for controlling gushing water with EPEM. Laboratory experiments on grouting plugging for karst pipeline gushing water are then conducted to validate the feasibility and practicality of the EPEM theoretical model. Finally, the research outcomes are applied to a tunnel project in a coastal karst area, where grouting parameters calculated based on the theoretical model successfully achieve effective gushing water plugging. These results indicate that the water-plugging theory of EPEM grout has strong engineering applicability and can support the resilience enhancement of coastal karst tunnel infrastructure.