Principle And Technology Of Rock Burst Prevention And Control In Layered Mining Of Huge Thick Coal Seam In Barapukuria Mine

Barapukuria coal mine(Barapukuria Mine for short),located in Bangladesh,is a typical rock burst mine with extremely thick coal seam.There have been many rock burst accidents in the mining process.At present,the average thickness of Ⅵ coal in the south wing mining area is about 39 m,and the stratified mining method is adopted.Coupled with the occurrence of hard thick layer roof and the influence of complex geological structure,rock burst frequently appears in the process of stratified mining in the mine working face.Therefore,on the basis of the existing research results,the influencing factors of rock burst under the condition of layering mining of extremely thick coal seam are analyzed,the evolution characteristics of overlying rock structure of multi-layering working face are revealed,the mechanism of rock burst occurrence under complex mining environment is explored,reasonable pressure relief measures are put forward for layering working face region,and the location selection of mining roadway under layering working face is correctly guided.Combined with efficient local anti-impact measures of working face to ensure the safety of mining of layered working face of extremely thick coal seam.The main achievements of this thesis are as follows:1)On the basis of analysis of influencing factors of mine rockburst risk,it is believed that geological structure,isolated working face,external fault of lower layer hole cutting and coal pillar of stoping line,etc.constitute the characteristic factors inducing mine rockburst under the mining condition of multi-layer working face of extra-thick coal seam in Barapukuria Mine.2)Based on the principle of rockburst and dynamic load superimposed induced shock in coal mine,the impact danger type of Barapukuria Mine stratified mining face is determined to be compound of dynamic and dynamic load superimposed.It is clear that the overburden fracture and structural evolution under the condition of layering mining of extra-thick coal seam are the main reasons to induce dynamic and static load in stope.3)The principle of pressure relief and impact prevention for stoping roadway at fault spacing in isolated mining face under the condition of stratification mining is revealed,and the comprehensive stress influence Angle index of coal pillar floor stress reduction zone is obtained,which guides the choice of stoping roadway at fault spacing in working face,and plays a good role in pressure relief and impact prevention for surrounding rock of roadway.On the background of pressure relief and impact prevention during the overstretching zone of 1210 D island face and 1210 working face in Barapukuria Mine,a series of pressure relief and impact prevention schemes have been put forward and implemented,including the measures of large diameter drilling of coal body,coal body blasting precracking,working face and roadway roof breaking,etc.,and the effect of pressure relief and impact prevention is remarkable.This thesis has 58 figures,5 tables and 81 references.