Study On The Feasibility Safe Mining Of Coal Seams Under Ruxi River In Luerjing

The ruxi river with a width of 25⁴0m,a depth of 0.3¹.5 m and a flow of 0.381¹5.428 m3/s is distributed above luer coal mine.Therefore,it is necessary to carry out feasibility study on safe mining of coal resources under ruxi river for safe and reliable mining of coal under the river.Rivers at home and abroad is presented in this paper and frontier technologies,on the basis of safe mining under water body in reed well your springs under the safe mining of coal seam no.3 as the research object,and unifies your springs around borehole data,systematically analyzes the reed two Wells of coal seam mining method process,your springs under the mining surface hydrological geology,the hardness of roof strata and the main working bed strata structure features.In addition,the rock mechanics and hydrology properties of 3 coal seam roof samples were tested in the mine,an engineering geological model for mining under ruxi river was constructed,the overlying rock failure movement evolution rule was simulated by FLAC^3D,and the technical scheme for mining under the river was compared.The following results were obtained:?1?There are ruxi river,quaternary loose aquifer,cretaceous aquifer,water-measuring aquifer and stone piertum marl aquifer overlying the coal seam under the river.The hydraulic connection between the aquifers is poor,which is conducive to the safe mining of the coal seam under the river.?2?The main coal seam under ruxi river is 1.79⁴.29 m,with the average coal thickness and dip Angle of 2.06 m and dip Angle of 250 m,respectively.Currently,the upper limit elevation of mining under the river is designed to be+70m,and the minimum coal and rock column height reserved is 101.9m.?3?The roof of the coal seam under the river is mainly composed of mudstone,limestone and siltstone,with the compressive strength of 32.61-50.67mpa,which belongs to the type of medium-hard overburden rock.The hydrology experiment shows that it has good water resistance and crack resistance.?4?FLAC^3D numerical simulation software was used to simulate the evolution law of vertical stress,shear stress and displacement of mining surrounding rock under different excavation width and excavation progress of coal seam 3 of exploration line 13-14 in luer mine.?5?According to the"three lower"coal mining code,the maximum mining height under the riverbed is 4.0m and the type of hard overburden is calculated.The waterproof safe coal and rock pillar is 95.72m,which is smaller than the designed minimum coal and rock pillar of 101.9m,which meets the code requirements.?6?The regulation and control measures for preventing water inrush and sand under the river by adopting uplinking mining method and preventing the overlying strata of coal seam from expanding up in the balanced failure height are formulated.To sum up:the upper limit of the designed+70m horizontal mining under ruxi river is safe and feasible.Picture[68]table[11]reference[60]...