Study of the velocity effect on the energy dissipation structure of overlying rock at a fully mechanized mining face

In this work, the law of fracture evolution in overburden rock is studied via theoretical research and physical simulation experiments. The regional scope of gas transport and storage areas for pressure relief was defined. The fracture field can be divided into a gas transport area, a gas storage area and a rock overburden compaction area with a separation amount of 1.4 m and a penetration degree of 0.6 of the overlying strata during mining. A characterization model of the gas transport and storage areas under different advancing speeds was constructed. According to the energy accumulation form, the “half-moon” shape of the energy dissipation structure and the criterion of the energy criterion of the dissipative structure of the overburden rock were established. The reasonableness of the criterion of dissipated structural energy of the overlying rock was verified via microseismic monitoring in the field. The energy dissipation structure had an important influence on the regional evolution of gas transport and storage areas during mining. The features of gas transport and storage areas under the infection of energy dissipation structures at different advancing speeds were elucidated. The location of the gas extraction borehole with pressure relief was optimized.