近距离煤层开采回采巷道布置方式及变形规律

Layout pattern and deformation law of mining roadwayin contiguous coal seam mining

神东矿区活鸡兔井1-2上煤与1-2煤的层间距仅为9~21 m,属于典型的近距离煤层群开采。12314运顺和12313回顺在1-2煤层中掘进,为了研究在1-2上煤开采过程中下煤层中预掘巷道的稳定性以及下煤层巷道的合理布置方式,通过现场巷道变形观测、物理相似模型试验及数值模拟计算的综合分析方法,得出1-2上煤层中巷道的变形规律及引起巷道变形的主要影响因素,并对下煤层巷道分别布置于上煤层采空区下与区段煤柱下的变形情况进行了对比分析。现场实测结果表明在上工作面采动和巷道开挖共同影响下,下煤层巷道两帮移近量最大值15 mm,顶底板移近量最大值17 mm,巷道变形量很小,不会影响巷道的稳定性。通过数值模拟研究得出当下煤层巷道均布置在上煤层工作面老采空区下时,巷道顶底板和两帮移近量终值分别为:27.9 mm,24.9 mm,巷道的变形量较小,上煤层开采不会影响下方巷道正常使用。将下煤层2个巷道均布置在煤柱下时巷道顶底板及两帮移近量均相对较大,但其巷道仍容易维护,同时相比于采空区下布置巷道更加容易布置锚索支护,大大增加了成巷速度,保障矿井安全高效生产。研究成果对于同类型地质条件矿区近距离煤层开采巷道布置及支护方案优化具有借鉴意义。

The distance between Coal seam 1-2upper and Coal seam 1-2 in Shendong mining area is only 9~21 m,which involves typical short distance coal seam mining.12314 transport and 12313 return are excavated in 1-2 coal seam.To examine study the stability of pre-excavated roadway in lower coal seam and the proper layouts of lower coal seam roadway in the process of 1-2upper coal mining,a comprehensive analysis has been made of on-site roadway deformation observation,physical similarity model test and numerical simulation calculation,with the deformation law of roadway in 1-2 coal seam and the main influencing factors of roadway deformation obtained.The deformations of the lower coal seam roadway arranged under the goaf of the upper coal seam and under the coal pillar in the section are compared and analyzed.The on-site test results show that under the joint influence of the mining of the upper working face and roadway excavation,the maximum displacement of the two sides of the roadway in the lower coal seam is 15 mm,and the maximum displacement of the roof and floor is 17 mm.The roadway deformation is very small,which will not affect the stability of the roadway.Through the numerical simulation research,it is concluded that when the roadway of the current coal seam is arranged under the goaf of the upper coal seam working face,the final values of the roof and floor of the roadway and the approach of the two sides are 27.9 mm and 24.9 mm respectively.The deformation of the roadway is small,and the mining of the upper coal seam will not affect the normal use of the roadway below.When the two roadways in the lower coal seam are arranged under the coal pillar,the roof,floor and two sides of the roadway are relatively large,but the roadway is still easy to maintain.And compared with the roadway arranged under the goaf,it is easier to arrange anchor cable support,which greatly increases the roadway forming speed and ensures the safe and efficient production of the mine.The research results could provide a significant reference for the roadway layout and support scheme optimization of contiguous coal seam mining in mining areas with the same type of geological conditions.