陷落柱对W矿3#煤层底板破坏和隔水性能的影响

为了评估陷落柱对煤层底板的危害,运用数值模拟对所选取的W矿3#煤层进行了分析。根据柱状图,建立了一种计算模型,采用RFPA2D模拟了采场推进时煤层底板的破坏情况,估算了底板破坏深度。结果表明：随着回采工作面的推进,矿压和水压造成的顶板的破坏高度逐渐增加;工作面推进到150 m前,覆岩破坏没有发展到关键层1;随着回采工作面的推进,矿压和水压造成的底板的破坏深度也逐渐增大,工作面推进到135 m时,底板的破坏深度不再发生明显的变化,此时底板破坏深度大约16 m。工作面推进到150 m时,泥岩层尚未贯穿,成为隔水关键层,底板不受含水层的影响。另外,研究表明：贯穿煤层和达到煤层的陷落柱对底板破坏的影响比未达到煤层的陷落柱对底板破坏的影响大。

Research of the Destruction and Water-resisting Ability of Floor of Subsidence Columns in W Coal Mine Seam 3

The damage resulting from subsidence columns in the coal seam of W Coal Mine was analyzed by numerical simulation.Based on the column of rock mass in this coal mine,the destruction of the roof and floor were simulated by using a numerical soft（RFPA2D） while long-wall mining was pushed on.Failure altitude of depth of floor was estimated.The results show that： when the extracting face of coal seam 3 was pushed on,the failure overburden resulting from rock pressure didn＇t grow to key stratum 1.The failure depth became larger when the workface still pushed on,and it didn＇t change any more when the workface was pushed on to 135 meters,the failure depth was about 16 meters.At this time the mudstone wasn＇t throughout and it was impenetrable,so it was considered as the water-resisting key stratum.The floor wasn＇t effected by aquifer.The results also show that：the influence which result from impenetrable subsidence columns and achieved subsidence columns was much more than from unachieved subsidence columns.