Abstract:
With the deep mining of coal resources, geological disasters such as rock burst and large deformation of surrounding rock caused by deep complex stress environment and mining disturbance become more and more frequent. It is urgent to systematically explore mining-induced mechanical behavior and energy evolution characteristics of coal under three typical mining layouts. Therefore, the mining stress paths of different mining layouts was designed in the test, the mining simulation test of coal under different mining layouts was realized using the conventional triaxial test instrument, and the mining-induced mechanical behavior and energy evolution characteristics of coal under different mining layouts were revealed. The experimental results show that, compared with coal deformation characteristics of conventional triaxial compression, a few volume compression existed under mining conditions, and the dilatancy phenomenon occured earlier and more significantly. According to the sequence of protected coal seam mining, top-coal caving and non-pillar mining, the mining deformation of coal gradually increased, coal mining failure mode changed from tension shear failure to pure shear failure, finally tended to triaxial compression shear failure. Accompanying energy was larger, and mining impact was more severe. With the increasing depth, the accompanying energy in coal during mining increased, the degree of mining damage gradually increased, the safety and stability problem of coal under mining became prominent, and the mining difficulty also increased. These experimental results provided references and guidances for the safe and efficient mining of coal resources.