Mechanism of Rock Burst Induced by Hard Roof and Discussion on Hydraulic Fracturing Prevention and Control Technology

The dynamic load released after hard roof fracture, which superimposes with the static load inside the coal and rock mass, is an important force source condition causing rock burst disasters in domestic coal mines. According to two dimensions of rock stratum combination form and spatial position, this paper divides hard roofs into four categories: single/composite and near-field/far-field, and sorts out the disaster-inducing mechanisms corresponding to each type of roof. On this basis, it explains the essence of energy regulation of hydraulic fracturing, which realizes "reducing static load - weakening dynamic load - blocking transmission path" through artificial fracture network. In view of the current practical bottlenecks, such as the lack of quantitative criteria for collaborative disaster induction of composite roofs and the fact that main control stratum identification mostly relies on engineering experience, this paper proposes a prevention and control technology framework of "accurate identification of main control strata - three-dimensional collaborative fracturing above and below the mine - intelligent effect evaluation". The research results show that promoting the prevention and control work from "experience-based rock burst prevention" to "science-based rock burst prevention" is the key path to improve the prevention and control effect of hard roof rock burst.