基本顶断裂位置对窄煤柱护巷的影响及应用

针对天煜能源恒昇煤业埋深浅、煤层厚、顶板坚硬地质情况,留设煤柱过宽,则浪费煤炭资源;留设过窄,则采动必定会破坏或损伤煤柱,导致相邻采区采空区和本采区采空区遗煤漏风氧化自燃的问题。在基本顶断裂位置围岩结构力学模型的基础上,分析了基本顶断裂线位置与关键块回转角和煤柱上覆载荷之间的关系,理论计算了煤柱宽度和基本顶断裂位置,研究得到:综放工作面留设窄煤柱时,必须考虑基本顶断裂线的位置,避免巷道于基本顶断裂位置下方掘进;基本顶断裂位置为3~5 m,护巷煤柱宽度最小为4.6~6.3 m,基本顶断裂线位置正处于所留煤柱上方,煤柱此时承受的压力较大,考虑该煤层为易燃煤层,因此需增加煤柱的承载面积,最终确定该矿9205机巷护巷煤柱的合理宽度为8 m,并提出了相应的锚网索支护方案。工业性试验表明,该方法确定的煤柱宽度科学、可靠,采用的支护方案有效减小了巷道变形,增强了窄煤柱稳定性。

Impact and application on narrow coal pillar for roadway protecting from fracture position of upper roof

In allusion to the geology situation of shallow buried depth，thick coal and hard roof in Hengsheng Coal Mining of Tianyu Energy，retained too wide coal pillar will waste coal resources，and，On the contrary，the pillar retained too narrow will be destroyed or damaged because of the mining activity，thus leading to the problem of air leakage，spontaneous and combustion in adjacent goaf and in local goaf.Based on the surrounding rock structure mechanical model of cracked point of main roof，analyzed the relationship between fracture position of upper roof and elevation angle of key block and overlying load，calculated the coal pillar width and fracture location of upper roof.The research reaches the conclusion that it is necessary to think about the location of fracture line of upper roof when retained narrow pilla in fully mechanized working face，and to avoid excavating roadway under the breaking line of upper roof.Besides，the fracture position of upper roof is 3-5 m，and minimum width of coal pillar is 4.6-6.3 m，As the fracture location of upper roof is just above the designed coal pillar，the coal pillar bears the greater pressure，and consider the coal seam is flammable，so it is necessary to supplement the pilla bearing area.Finally，ascertaining that the reasonable pilla width of 9205 lane roadway is 8 m and providing the corresponding the bolt-mesh-anchor support scheme.The industrial test show that the coal pillar width is scientific and reliable，and the adopted support scheme effectively reduce the roadway deformation and enhances the stability of narrow coal pillar.