近距离煤层采空区下综采支架合理工作阻力研究

Study on reasonable fully-mechanized mining support working resistance under gob of contiguous coal seam

针对近距离煤层采空区下综采工作面顶板压力实测值与"传递岩梁"理论计算值存在显著差异的问题,以大柳塔矿21305综采工作面为背景,采用理论分析方法确定了顶板压力力源,采用位态方程和实测统计相结合的方法,研究了采空区下综采工作面支架合理工作阻力的确定方法。结果表明:采空区下综采工作面矿压规律因受多种复杂因素的影响,表现出明显的特殊性与差异性,直接顶和基本顶重力以及上覆采空区矸石附加静载荷组成了工作面支架上的顶板压力;采空区上方矸石随着工作面支架前移而在工作面上方附近及时随动,对其产生附加静荷载作用,导致了21305综采工作面顶板实测压力值相比"传递岩梁"理论计算值明显增大;支架均值偏阻力12 326 kN和支架均值上阻力12 903 kN所对应的顶板控制效果均极好,超限比例均较小,但当支架合理工作阻力选为12 903kN时,超限比例为0,支架工作阻力富裕程度较高,因此本着降低生产成本,减少投资的原则,选取12 326 kN为21305工作面的支架合理工作阻力。

In view of the significant difference between the actual measured value of the roof pressure of the fully-mechanized mining face under the gob of contiguous coal seam and the calculated value by the"transferring rock beam",the theoretical analysis method is used to determine the roof pressure source of No.21305 fully-mechanized mining face of Daliuta Mine for force source.The method of combining position equation and measured statistics is used to determine the reasonable support working resistance in fully-mechanized mining face under the gob.The result shows that the underground pressure law of fully-mechanized mining face in the gob is affected by a variety of complex factors,showing obvious particularity and difference.The roof pressure on the working face bracket is composed of the direct roof and basic roof rock weights and the additional static load of the gangue from the overlying gob.The gangue above the gob will move in a timely manner in the vicinity of the working face as the support of the working face moves forward,resulting in additional static load effect on it.The theoretical calculation value of"transfer rock beam"has increased significantly;the support average deflection resistance of 12326 kN and the support average upper resistance of 12903 kN correspond to excellent roof control effects,and the overrun ratio is small.But when the reasonable support working resistance 12903 kN is selected,the overrun ratio is 0 and the support working resistance is relatively high.Therefore,in line with the principle of reducing production costs and reducing investment,the reasonable working resistance of the bracket in No.21305 working face is 12326 kN.