不同采-留-充开采方法下地表沉陷控制研究

Study of mining subsidence control under different mining-filling methods

基于浅埋煤层开采下的地表沉陷控制理论及控制方法,提出不同开采方法相结合的开采模式。以关键层理论为依据,试验研究为基础,并结合数值模拟分析,研究了不同采-留-充相结合的开采方法对该矿区地表沉陷的控制作用。结果表明:在充填材料中加入膨胀剂能提高充填体的接顶率;采用采-留结合的方式开采时,采25 m留25 m时地表变形最小,煤柱能够保持长期稳定性;采用采-留-充开采时,若完全置换留设煤柱,即置换25 m煤柱时,充填高度需达到4.5 m,此时充填高度等于采厚,可有效控制地表变形;若置换20 m煤柱时,充填高度只需达到4.3 m,此时充填体最终抗压强度为7.41 MPa,能够维持充填体的长期稳定。

Based on the theory and method of surface subsidence on shallow buried coal seam and the key strata theory,mining mode with the combination of different mining methods was put forward. The experiment study and the numerical simulation were applied to analyze the surface subsidence in the mining area though different mining-filling methods. The results showed that the rate of roof-contact would be raised if some bentonite was put into the filling materials. If the method of strip mining was adopted,the mining width and leaving width of the coal pillar would be 25 m. In that case,the surface subsidence could be minimized and the long-term stability of coal pillar could be maintained. If the pillar was replaced fully,the filling height should be reached 4. 5 m that was equal to the mining height,which was enough to ensure the stability of filling body for a long time. If 20 m pillar was replaced,the filling height could be reached 4. 3 m and the strength of filling body could reach to 7. 41 MPa,Which could maintain the stability of the filling body for a long term.