LAUSR

Laboratory testing is an efficient way to study the deformation and failure mechanisms of outburst coal. However, existing devices can only perform static loading tests on gas-adsorbed coal, which is not necessarily the stress condition encountered in coal seam outburst. Additionally, the traditional testing methods used by existing devices are not conducive to acquiring the dynamic performance of gas-adsorbed coal. In this study, a novel apparatus was developed to visualize gas-solid coupling. The apparatus can perform combined loading corresponding to a “static stress + impact disturbance” and a “static stress + gas pressure relief disturbance” on gas-adsorbed coal. The complex dynamic characteristics of the gas-adsorbed coal are comprehensively monitored by high-speed photography and a self-developed circumferential displacement test device. The effectiveness and reliability of the novel apparatus were confirmed by carrying out mechanical tests on gas-adsorbed coal subjected to a pressure relief disturbance and an impact disturbance. The test results showed that a dynamic disturbance can cause a sudden drop in the bearing capacity, a sudden increase in the volumetric strain, and rapid crack propagation in gas-adsorbed coal. The disturbance can even induce coal burst failure, which is very similar to the outburst phenomenon. The developed scientific apparatus can be used to study the deformation and failure mechanisms of gas-adsorbed coal under combined dynamic and static loading.