极近距煤层联采覆岩结构演化规律研究

Study on the evolution law of overburden structure in combined mining of very close seam

不同的地质构造决定了煤层赋存情况各异,为有效提高煤炭资源采出率,使煤炭资源得到最充分的回收,通过对某矿极近距煤层(即8#、9#煤层)上覆岩结构、顶板垮落特征进行综合分析,并运用数值模拟的方法对围岩垂直应力分布情况进行说明,研究了其联采覆岩结构演化规律,主要得出,初采时9#煤层长壁工作面在8#煤层刀柱采空区下时,上覆顶板结构没有变化;工作面推进至8#煤层工作面煤柱边缘时,上方煤柱失稳破坏,失稳煤柱承受载荷会向前后临近两个煤柱转移,导致临近两个煤柱随动失稳,临近两个煤柱之外的煤柱稳定。

Different geological structures determine the occurrence of different coal seams.In order to effectively improve the recovery rate of coal resources and make the most full recovery of coal resources,a comprehensive analysis is made on the overlying rock structure and roof caving characteristics of a very close coal seam(i.e.8#and 9#coal seams),and the vertical stress distribution of surrounding rock is explained by numerical simulation method,and its connection is studied.The evolution law of mining cover rock structure mainly shows that when the long wall working face of 9#coal seam is under the goaf of 8#coal seam cutter pillar,the structure of the overlying roof does not change;when the working face is pushed to the edge of the coal pillar of 8#coal seam working face,the upper coal pillar is unstable and destroyed,and the load of the unstable coal pillar will transfer to the front and back adjacent two coal pillars,resulting in the dynamic instability of the adjacent two coal pillars,and the adjacent two coal pillars The outer coal pillar is stable.