The Study Of Law Of Stope Pressure Before And After The Hard And Thick Roof Is Weakened

Although the control of hard roof’s technology and theory has obtained certain achievements for years,but it still affect the normal production of coal mine exploitation under the condition of hard roof, not only increased the cost of mining, but brought great hidden trouble to the mine safety production.Therefore,it is very important to weak for stope hard roof.Taking xinji coal mine210108mining face as the research object,We builded first weighting pechanical model and periodic pressure model to predict the pressure situation.Taking210108as the first mining face, We’ve developed blasting weakening of stope strong sandstone roof plan at the beginning of the mining,carried out advanced deep hole blasting weakening technology processing. We analyzed the law of mine pressure appear, support load changes,concluded the circumstances of weighting through the field monitoring measurement points under the condition of sandstone roof weakening.Along with the advancement of stoping constantly,the face roof no longer makes blast weakening processing at the end of exploitation,but we still monitor real time pressure under the condition,and analyzed periodic weighting under the condition of no weakening blasting. We compared the law of mine pressure appear in the same face,but the face roof mining was managed in a different way, and evaluated the effect of deep hole blasting in advance in the thick sandstone hard roof.Through the analysis and research, the main conclusion as follows:Fristly,We established xinji coal mine210108fully mechanized face roof mechanical model, analyzed the mining thick hard roof breaking rule. We get the first caving step distance on an average of85.2m, Periodic weighting interval on an average of34.8m by the theoretical calculation.Secondly, We get the law of the mine pressure before and after the roof control blasting on210108fully mechanized face through mining pressure field testing and analysis. We get the first caving step distance on an average of41.33m, Periodic weighting interval on an average of19.08m by the theoretical calculation,When loose blasting is not adopted,the average is24.6m.Practice has proved that it improved the fall of the hard roof caving, prevent the suspension of large roof effectively, ensured the safety of the210108fully mechanized face in mining, and provided a scientific basis in xinji coal mine210108fully mechanized face hard roof processing when the210108fully mechanized face was made advanced deep hole pre-splitting blastingIn this paper, under the condition of strong thick roof safety mining of fully mechanized mining and roof control, has a certain guiding significance and reference value.