中近距离煤层同采巷道变形破坏规律及其控制

Deformation and failure rules and control of roadway in simultaneous mining of middle and near coal seams

针对布尔台煤矿上下煤层同采出现巷道剧烈变形破坏的情况,通过现场实测和FLAC3D数值模拟获得本煤层开采及下煤层开采对保留巷道变形破坏的阶段性特征及巷道掘进、本煤层回采、下煤层回采等不同阶段保留巷道的最终塑性区分布特征,即同煤层一次采动阶段巷道表现为变形随滞后工作面距离增加而增大,并在滞后200~400m时趋于稳定,塑性区最大深度由1.5m扩展至2.25m并稳定,上下煤层同采时留巷产生剧烈变形破坏,滞后段变形破坏急剧增加,呈现不规律性,塑性区由2.25m急剧扩展至6m。基于此,提出应力调控方法,即内错距离大于120m时,保留巷道在上下煤层同采时塑性区将大大减小,通过现场实践,将内错距离实际调控至508m,巷道变形得到有效控制。

For Buertai coal mine with up and down coal mining machine failure,severe deformation of roadway obtained by field measurement and FLAC 3D numerical simulation for the coal mining and coal mining under the retention and the stage characteristics of roadway drivage roadway deformation and destruction,the coal mining,coal mining under different phase reserves the final distribution characteristics of the plastic zone of roadway,namely with a mining stage of coal seam roadway show the deformation increases with increasing lag working distance,and tends to be stable when lag 200-400 m,the maximum depth of the plastic zone expands from 1.5 m to 2.25 m and stable,with up and down coal mining in a dramatic deformation damage left lane.The deformation and failure of the lag stage increase sharply,showing irregularity,and the plastic zone expands sharply from 2.25 m to 6 m.Based on this,the method of stress control is put forward,that is,when the inner displacement distance is greater than 120 m,the plastic zone of the reserved roadway will be greatly reduced when the upper and lower coal seams are working together.Through field practice,the inner displacement distance is actually adjusted to 508 m,so that the roadway deformation is effectively controlled and the engineering effect is good.