Research on mechanical response of artificial dam under gas explosion in roadway

When a gas explosion occurs in a mine, the explosion shock wave can damage the water storage dam, leading to a large amount of water gushing out of the goaf, and even causing gas water coupling disasters. Therefore, the stability of artificial dams under extreme conditions is of great significance for mine safety. Currently, there's a lack of research on the mechanical response features of underground artificial dams propagating with gas explosion shock waves. In order to solve the above problems, the LS-DYNA software is used to simulate the impact of gas explosion in roadways on the mechanical properties of artificial dams. The stress state, deformation, and stress features of the explosion facing side, loess interlayer, and explosion backing side are studied. The dynamic response process of artificial dams under the action of gas explosion shock waves in roadways is analyzed. The analysis results of the load distribution on the surface of the artificial dam indicate that when an explosion occurs inside the roadway, the explosion load on the explosion facing surface of the artificial dam is unevenly distributed. At the same time, in the intersection area of various underground structures, the reflected overpressure has a significant strengthening effect due to the convergence and superposition of reflected shock waves. With the rapid release of explosive energy, the impulse loading time history curve of the central measuring point on the explosion facing surface exhibits a three-stage change feature. When the gas volume is 200 m³, the maximum impulse of the central measuring point on the explosion facing surface can reach 0.04 MPa·s within 500 ms of explosion. The results of deformation and stress analysis on the surface of the artificial dam indicate that within 0-500 ms, the central part of the explosion facing surface is always under compressive stress. The maximum lateral displacement of the central node is 0.319 mm. Due to the effect of cutting, the artificial dam is subjected to tensile stress around it, where the maximum tensile and shear stresses occur. The dynamic response of the loess interlayer is in the order of "compression - compaction - plastic deformation - pressure transfer", during which the loess plays a buffering role, with a maximum displacement of 0.067 5 mm. The wall of the explosion backing side undergoes mechanical response due to the compression of the loess interlayer. But the stress is relatively small, and the outer wall is basically in a safe state.