Study on Sealing Mechanism of Three-Stage Sealing Under Transient High-Pressure Gas Rock Breaking

In transient high-pressure gas rock breaking, resilient sealing materials can reduce energy loss during rock breaking and ensure the effectiveness and safety of the operation. This study, utilizing experimental data and finite element analysis, investigates the impact of transient high-pressure gas on sealing methods. It compares the traditional single-layer concrete sealing with a novel three-stage concrete sealing method, highlighting its advantages. Furthermore, a three-stage approach is used to analyze the mechanical evolution of different sealing layers, and the sealing mechanism is revealed through energy-absorption analysis. Research findings indicate that the traditional single-layer concrete sealing method experiences severe damage, with a maximum damage value of 0.26. In contrast, the three-stage sealing method exhibits significantly less damage (mostly < 0.2), effectively improving sealing efficiency. The three-stage sealing method generally demonstrates lower stress levels compared to the single-layer concrete sealing method. After passing through the gravel and soil layers, the impact-induced stress becomes relatively stable, with stress levels at the center gradually approaching those at the hole’s walls. The central portion of the gravel layer shows a greater energy absorption effect than the two boundary areas, while the soil layer exhibits a linear relationship between deformation and energy absorption. The three-stage sealing method weakens the impact through a structural approach of “pressure-absorption-pressure”, where the gravel layer primarily disperses pressure, while the soil layer provides energy absorption and cushioning. The research findings have significant implications for the safe application of transient high-pressure gas rock breaking technology.