Researchers reveal influence of cyclic dynamic disturbance on coal-rock evolution and zoning

In coal-rock formations, many micro-fractures exist, and the expansion of these micro-fractures is the internal catalyst for the macroscopic destruction of coal-rock. Moreover, the occurrence state of gas changes with the expansion of micro-fractures. In engineering practice, most coal-rock mass needs cyclic operation in the blasting excavation or mechanical drilling, and the dynamic load of coal-rock mass is cyclic impact load.