Study On The Impact Mechanism And Prevention Technology Of Mining With Layered Caving In Extra Thick And Hard Coal Seam

Rock burst is the destruction of the mechanical balance of surrounding rock mass,and the redistribution of the original stress leads to a huge,large,strong,strong,seismic,dynamic,synchronous,companion,with,with,with,with,with,with,,with,with with,with,with,large,large,coal,rock,block,by,thrown out,one kind,dynamic,force,disaster,is,one kind,right,coal,mine,production,zone,come,huge,powerful,threat,ening,mine,pressure,apparent,shape.There are many factors affecting the rock burst under the condition of layered mining irn Extra-thick and hard coal seam,including roof,pillar,structure and coal and rock mass properties,but the main forms of impact are floor impact.The damage scope of floor impact is large,the mech,anism is complex,and the prevention and control is difficult.Therefore,it is necessary to advance the impact mechanism and prevention technology of layered fully mechanized caving mining in Extra-thick and hard coal seam.Conduct research.In this paper,the prevention and control of rock burst in ultra-thick coal seam mining in Hujiahe Coal Mine 401102 face are studied.By means of theoretical analysis,numerical simulation and field measured data analysis,the causes of rock burst in Extra-thick Coal Seam Mining are divided into six aspects:mining,mining,depth,coal,seam,impact,dip,coal,seam,thickness,coal pillar and roof lithology.Based on the study,it is proposed that the main form of impact in the mining of extra-thick and hard coal seam by layered top coal caving is floor impact.Based on the results of in-situ stress test in Hujiahe Coal Mine and combined with the principle of dynamic and static overlay induced rock burst,the mechanism and types of floor rock burst induced by slicing mining in Extra-thick seam are put forward,and the calculation model of floor stress is established.Through the analysis of the roof movement law in slicing mining in extra-thick seam,the main inducing factors of dynamic load in working face of Hujiahe Coal Mine are the weighting of the old roof.Mining activities lead to local high stress concentration in coal and rock mass,among which mining disturbance leads to the movement of roof or even overlying strata,and high-energy earthquake caused by faults is the main dynamic load source of working face.The regularity of energy and frequency variation of mine quake is analyzed.The evaluation index value is established by using impact deformation energy index and shock wave CT technology.The regional combined monitoring of dynamic and static loads is realized.Combining with the comprehensive index method,the dangerous areas of coal pillar area are divided.The methods of local pressure relief and reducing stress concentration are put forward to control the rock burst disaster and relieve the danger.Technology and precautionary measures are put forward according to different dangerous grades.Pressure relief treatment schemes mainly consisting of large diameter borehole pressure relief,coal body pressure relief blasting and roof deep hole blasting are put forward.Field application shows that pressure relief measures can change the energy storage structure of surrounding coal and rock mass,effectively reduce the stress concentration degree in coal and rock mass,and have obvious scour prevention effect.It provides a rationale for safe mining under similar conditions.On the basis and reference.