The Study On Drillhole Pressure Relief Preventting Rockburst In Coal Mine

Rock burst in coalmines is one of the complex dynamic phenomena and is always one of the difficult problems on rock mass mechanics and mine pressure. In recent years, with the excavation depth of coal mining increasing, the mine numbers of rock burst occurrence also increase obviously, which greatly threaten the mine production and safety, so it is necessary to research these prevention measures deeply. In this thesis, many research methods, such as field measures, theory analysis, and numeric simulation, are used to found mechanics models, further the influence factors of abutment pressure distribution are researched in the condition of gravity field. By analyzing the experiment results of size effects of uniaxial compression strength of coal sample and the numerical simulation results based on Weibull distribution, the two coefficients affecting any coal samples strength, and the regressive formulation calculating original coal and coal mass strength with standard coal sample strength are gained. The process of drillhole pressure relief is simulated to deeply research the rock burst prevention. Based on the numerical simulation, this thesis analyses the influence of different coal seam pressures and different coal seam strength on the destroy radius of drillhole,then by theory analysis and regression analysis, draws the relation between the destroy radius of drilling hole and coal steam strength, coal seam pressure and drilling hole diameter. The results are used to guided to prevent rockburst in coal mining. The method of drillhole pressure relief is applied in the Dongtan Mine, the effect of releasing rockburst danger is good. Drillhole pressure relief can be applied in advance to decrease the influence to production, is suitable to all kinds of coal seams and the mining conditions, and has the guidance function to the prevention of rock burst.