Study On Reasonable Scope Of Pressure Relief And Drainage In Tingnan Coal Mine204Working Face

Along with the coal mining depth and mining intensity increasing, and the caving method of roof-control methods gradually popularizing, coal production is increasing, at the same time, the threat of gas is also gradually increasing. The controlling of coal mine surrounding rock and high efficiency and safe production are facing the severe test.On the basis of the rock crack evolution and gas drainage engineering studies at home and abroad, based on coal Mining science, coal mine gas prevention and control theory and engineering application, seepage theory and numerical simulation, some explorations were carried out: Through gas basic parameter measurement and emission prediction, analyze the large mining height gas source and the gas control key;Combined with previous test results and a large number of theory,and through the research of overburden rock by the mining influence, a relationship between stress and seepage is concluded:permeability can be expressed by the exponential function of vertical stress. And get the rule of between the permeability and effective stress in different rock through tests;Using numerical simulation, study the rule of the mining impact on strata stress,using experiment get relationship between the permeability and effective stress,overlying rock permeability distribution and the relationship between the working face advancing distance, divide distressing extraction reasonable range;Used the measure of gas extraction scalar, gas extraction effect is good when the last mining hole is located in middle and high angle transition zones, determine the discharge pressure of the gas extraction reasonable layer. Optimize the gas extraction based on the analysis of mining scope in front of the discharging pressure range. By the means of putting high level and middle level pressure relief and drainage combined with other extraction methods into effect in Tingnan coal mine204working face, which reduces the gas emission of goaf and adjacent layer, controls the gas overrun of the working face and the upper corner effectively, greatly improves the gas extraction rate, provides a stable and high gas density for gas utilization.