煤矿过沟开采突水溃砂临界水力坡度计算及应用

Water Bursting Quicksand Critical Hydraulic Gradient Computation and Its Application in Coal Mining under Ditch

为了研究浅埋煤矿综采工作面在过沟开采过程中发生突水溃砂灾害的临界条件,在松散含水层液化流动的临界水力坡度推算基础上,利用承压含水层单井非稳定流抽水模型导出了实际水力坡度求解公式,提出了突水溃砂灾害发生的临界判据。并利用临界水力坡度、实际水力坡度的计算方法及突水溃砂的判定方法对哈拉沟煤矿22404工作面过沟开采突水溃砂风险性进行了预测,结果表明:该工作面的实际水力坡度为3.595,实际水头高度大于12.64 m,均小于其临界水力坡度和临界水头高度,工作面具有突水溃砂的风险。根据计算结果,对该工作面上覆松散富水层在井下进行了预疏放水和注浆固砂处理,有效预防了突水溃砂灾害的发生,保障了工作面的生产安全。

To study the water bursting quicksand hazard critical condition of shallow buried coalmine fully mechanized face mining un- der ditch process, based on loose aquifer liquefaction induced flow critical hydraulic gradient prediction, using confined aquifer single well unsteady flow pumping model derived actual water gradient solving formula. Then put forward water bursting quicksand hazard oc- currence critical criterion. Through computing methods of critical hydraulic gradient, actual hydraulic gradient and water bursting quicksand judging method carried out prediction of water bursting quicksand risk in Hargol coalmine working face No.22404 mining under ditch. The result has shown that the face actual hydraulic gradient is 3.595, actual height of waterhead is higher than 12.64m, all less than its critical hydraulic gradient and critical height of waterhead, thus the face has water bursting quicksand risk. According to computed results have carried out underground advanced water drainage and grouting sand consolidation for overlying loose water-rich layers, effectively prevented water bursting quicksand hazard happening and guaranteed working face production safety.