Directional long horizontal drilling hydraulic fracturing technology (DLHDHF) can prevent and control the occurrence of rock burst disasters by controlling the hard roof in the near field. Therefore, it is exceedingly significant to enhance the pressure relief effect by determining the appropriate fracturing scheme. Taking Number 140202 working face of a coal mine as the engineering background, this research first identifies the disaster key stratum through field monitoring data and theoretical analysis. Based on these findings, a FLAC3D numerical model was established to analyze the pressure relief effects between conventional hydraulic fracturing and DLHDHF comparatively. The theoretical relationship linking key layer thickness to the tensile deformation-induced elastic energy accumulated prior to fracture is established, thereby elucidating the mechanism of pressure relief via DLHDHF. Furthermore, orthogonal experiments were designed to research the evolution patterns of roadway surrounding rock stress, plastic zones, and energy distribution under different schemes, and the optimal parameter design of fracturing scheme was obtained. The results demonstrate that DLHDHF more effective than conventional methods for pressure relief. It works by forming a plastic zone within the key layer, thereby releasing stored elastic energy and reducing the periodic weighting interval. Borehole spacing is identified as the dominant factor influencing roadway surrounding rock deformation and damage. A strong correlation exists between borehole spacing and three key indicators: stress concentration coefficient, plastic zone area, and energy accumulation magnitude. Considering variance analysis results, site construction conditions, and economic benefits, the optimal operational parameters were determined as: 150 mm borehole diameter, 8 m borehole spacing, and 20 m fracturing spacing. The research results of this paper can provide some reference for the design of rock burst prevention and control scheme.
Du et al. (Thu,) studied this question.