Study On The Influence Of Downhill Protection Coal Pillar On Mine Safety Mining In Middle Part Of Barapu Culia Coal Mine

Barapukuria Coal Mine(Bangladesh Barakupuria Mine),surface is covered with more than 100 meters thick loose strong aqueous layer Upper Dupi Tila.In addition to the LDT aluminum clay clay barrier layer with about 15-25m thick at the bottom of the UDT,Almost there is no impermeable rock in overlying rock,the Mine is subjected to water inrush,impact pressure,ignition and high temperature heat damage more disasters.At the end of the second slicing mining,the coal pillar mining has become the key problem of mine safety mining of three points.Based on the analysis of the geological and mining conditions,this paper makes a comprehensive analysis by means of theoretical analysis,numerical simulation and empirical analogy,In this paper,the safety mining of the coal pillar under the protection of the mining area in the middle of the mining area is analyzed and determined.Based on the analysis of geological and mining conditions,It is concluded that the mining of Protective coal pillar can release the high stress on the coal pillar,reduce the impact of mine pressure threat,protect the integrity of the LDT barrier layer,ensures under the UDT strong watery loose layer The Key Technology of the Third Stratified Safety Mining.Based on the analysis of the distribution pattern of the goaf on both sides of the coal pillar,the inclination of the working face of the coal pillar and the factors such as the water inrush and the roof management,it is determined that the downhill working face adopts longwall oblique propulsion.Based on the calculation of the depth of the high stress failure zone of the bottom of the coal pillar,This paper analyzes the influence of down hill coal pillar mining on the roadway in the coal seam floor,and the results of numerical simulation show that the mining of working face of down hill coal pillar has little influence on the roadway 30 meters away from the coal seam floor.The 4rm and 6m mining are analyzed by numerical simulation,The development height of the plastic zone in the overlying strata and the high stress release above the coal pillar and degree of influence on the LDT barrier,The results show that the 4m mining height of coal pillar,after first and second layered mining high stress formed in mountain coal pillar effectively released,reduce the LDT aquifer tensile deformation degree,which is not only beneficial to the safety mining of UDT water,but also it is beneficial to the prevention and control of rock burst.On the basis of above research results,combined with the domestic and the Barapukuria coal mine first and second floor mining water prevention,prevention of rockburst experience,The mining scheme of the down hill coal pillar is determined,and the safety technical measures are formulated.The research results have certain reference value for the design and implementation of the three layer mining in the mine.