近距离煤层综放开采矿压显现规律研究
Study on mine strata behavior law of fully-mechanized top coal caving mining in contiguous coal seams
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摘要: 为深入研究近距离煤层综放开采矿压显现规律,以六家煤矿SⅡN26-7工作面为研究对象,采用数值模拟和现场实测方法对顶板运动规律、围岩应力规律和工作面支架工作阻力进行了分析。UDEC数值模拟结果表明:在上部6-6号煤层开采的影响下,SⅡN26-7工作面初次来压步距和周期来压步距均有所降低,应力峰值由24.1 MPa降低至17.0 MPa,影响范围由40 m增大至120 m。通过工作面液压支架工作阻力监测,在上部采空区作用下,工作面支架初撑力偏低;工作面初次来压步距平均为29.9 m,周期来压步距平均值为13.6 m,周期来压期间动载系数约为1.13。研究表明:在上部采空区作用下,工作面超前支承压力和顶板来压步距均有所降低,矿压显现强度有所减弱。Abstract: In order to deeply study the mine strata behavior law of the fully- mechanized top coal caving mining in the contiguous coal seams,based on No.SIN_26-7 coal mining face in Liugjia Mine as the study object,the numercal simulation and sie actual measuring method were appied to analyze the roof movement law,the surrounding rock stress law and the working resistance of the powered supports applied in the coal mining face. The UDEC numerical simulation results showed that under the infuence of the cal mining in the top No.6-6 seam,the initial of weightng span and the periodical roof weighting span of No.STN_26-7 cal mining face were all reduced,the stress peak was reduced from 24.1 MPato 17.0 MPa and the infuence scope was increased from 40 m to 120 m. With the monitoring and measuring on the working resistance of the powered supports applied in the coal mining face,under the role of the top goaf the initial support force of the powered supports applied in the coal mining face was low. The initial roof weighting span of the coal mining face was 29.9 m in average,the periodical roof weighting span was 13.6 m inaverage and the dynamic loading c efficient was 1.13 during the periodical roof weighting. The study showed that under the role of the top goaf:he advanced support pressure of the coal mining face and the roof weighting span were all reduced and the intensity of the mine strata behaviorwas reduced.