不同充填率分层充填开采覆岩三带研究分析OA

In view of the problem of multi-layered filling mining in shallow buried depth and extra thick coal seams,taking the south wing filling mining experimental zone of Baijigou Coal Mine as the research object.Based on the specific engineering geological environmental conditions of this area,similarity simulation and numerical simulation research are conducted on the three zone distribution laws of layered filling mining under parameter conditions with different filling rates.Through physical simulation experiments using similar materials,it is concluded that when the filling rate is 100%,the"eight"shaped fissures are developed to 10 m and the height of the fissure zone is 15.9 m after the completion of the four layered mining;When the filling rate is 90%,abscission layers occurred in local areas,and the fissure zone is further developed upwards,with a height of 22 m,the upper overburden rock is bent and deformed in a larger scale,with a bending subsidence zone height of 38.7 m;When the filling rate is 80%,a large number of fissures and abscission layers occurred in the upper overburden rock,the direct roof is broken,a collapse zone with a height of 10 m is formed and the fissure zone is developed to 50.6 m above the collapse zone.Through UDEC numerical simulation method,analyses are conducted at filling rates of 80%,90%,and 100%,respectively,it is concluded that with the gradual increase of the filling rate,the damage degree of overburden rock is effectively controlled,which also reflects the higher risk of fissure penetration caused by stress superposition in the layered mining of extra thick coal seams.