Principle and application of high pressure hydraulic slotting pressure relief and energy release in deep roadway

Abstract

Abstract The essence of deep roadway dynamic disaster lies in the sudden release of surrounding rock elastic energy. High-pressure hydraulic slotting (HPHS) has become a new method for pressure relief and energy release of roadway surrounding rock. In view of the lack of qualitative description of the response relationship between parameters of HPHS and pressure relief and energy release degree of roadway surrounding rock. In this paper, theoretical analyses, numerical simulations, on-site industrial practice, and other methods are comprehensively used to carry out relevant research work. First, the structure model of pressure relief and energy release of coal by HPHS in the deep roadway was established, the principle of pressure relief and energy release by HPHS was revealed, and the principles and methods for determining the pressure relief parameters such as the range of slot, the spacing of the slot hole, and the spacing of slot were proposed. Three evaluation indexes of pressure relief and energy release effect of coal after HPHS were proposed, namely, stress ratio of coal, elastic energy density ratio of coal, and displacement rate of the roadway rib. According to the evaluation indexes, the degree of pressure relief and energy release was divided into three levels: reverse pressurization, full pressure relief, and transitional pressure relief. Then, the FLAC3D numerical model was constructed, the level of pressure relief and energy release under different HPHS parameters was analyzed, and the optimal slotting parameters were determined. Finally, the on-site industrial practice was carried out in the 7312 working face of Xinhe Coal Mine. The effect test shows that the effect of pressure relief and energy release was remarkable after HPHS was adopted on the roadway surrounding rock, which can effectively reduce the risk of rock bursts. The research results can further improve HPHS technology systems, and provide a theoretical basis and technical reference for the stability control of deep roadway surrounding rock.