Mechanism and Control Technology of Rockburst Induced by Thick Hard Roof and Residual Coal Pillar: A Case Study

Rockburst caused by the fracture of thick hard roof and instantaneous instability residual coal pillar seriously jeopardize deep mining safety. This study takes Boertai Coal Mine, Shendong, China, as engineering background, in which dynamic mechanisms gob-side roadway surrounding rock are analyzed integrating field research, theoretical analysis, numerical simulation. The results show that overlying pillar, side abutment pressures, front pressures together induce high static stresses gob roadway, with peak values exceeding situ stress one order magnitude. High accumulated goaf-side can easily disaster. With working face advanced, overburdens caved succession, resulting a continuously decreasing width, once entered influence area pillar. As morphology pressure changes from “unimodal distribution” to “bimodal distribution,” gradually elastic state plastic state. When width is less than critical structure (THRRCPS) lose stability suddenly, strong load on roadway. In prevent rockburst under THRRCPS, regional local prevention measures adopted mitigate accumulation hydraulic fracturing technology large diameter relief drilling hole.