Mining-Induced Stress Control by Advanced Hydraulic Fracking under a Thick Hard Roof for Top Coal Caving Method: A Case Study in the Shendong Mining Area, China

Fully mechanized top-coal caving mining with high height, hard roofs and strong pressure are popular in the Shendong area, China. The occurrence of dynamic disasters, such as rock burst, coal gas outburst, mine earthquakes goaf hurricanes during exploitation process under roof conditions, pose a threat to safe production mines. In this study, characteristics overburden fracture fully height studied, technology advanced weakening by staged fracturing was proposed. results show that strata collapse form large “cantilever beams”, it is easy release huge impact kinetic energy, forming disasters. After implementation hydraulic fracturing, periodic weighting length decreases 32.16%, overhang reasonably effectively controlled. Ellipsoidal networks direction vertical working face, horizontal perpendicular near-linear planes dominated fractures were observed, accumulated energy greatly reduced. effectiveness innovation validated, stress transfer, dissipation disasters