Geology

Mechanics

Dissipation

Compression (physics)

Composite material

Acoustic emission

Deformation (meteorology)

Methane

Thermodynamics

Organic chemistry

Overburden pressure

Coalbed methane

Coal mining

Chemistry

Geotechnical engineering

Metallurgy

Materials science

Comminution

Physics

Coal

Journal of Rock Mechanics and Geotechnical Engineering

The mechanical behavior of coal is the key factor affecting underground coal mining and coalbed methane extraction. In this study, triaxial compression and seepage tests were carried out on coal at different gas pressures. The mechanical properties and failure process of coal were studied, as well as the acoustic emission (AE) and strain energy. The influence of gas pressure on the mechanical parameters of this coal was analyzed. Based on the conventional energy calculation formula, the pore pressure was introduced through the effective stress formula, and each energy component of coal containing gas was refined innovatively. The contribution of gas pressure to the total energy input and dissipation during loading was quantitatively described. Finally, the influence of gas pressure on coal strength was theoretically analyzed from the perspectives of Mohr–Coulomb criterion and fracture mechanics. The results show that the total absorbed energy comprises the absorbed energy in the axial pressure direction (posi...

Experimental investigations on effects of gas pressure on mechanical behaviors and failure characteristic of coals