Study On The Law Of Rock-burst Appearance In The Area Of Coal Seam Thickness Variation Of Jian-xin Mine

With the increasing depth of coal mining,and it brings about a series of mine pressure problems,among which the rock burst problem is particularly prominent,which is very destructive.There is a serious danger to the safety of the lives of the coal miners.A large amount of elastic energy accumulated in the surrounding rock is an important reason for its occurrence.Through field investigation,rock mechanics test,FLAC^3Dsoftware simulation and industrial test research method.Based on the 4206 working face engineering background of jianxin coal mine,this paper analyzes the influence law of coal thickness change on surrounding rock failure and puts forward the treatment plan.The main research contents and achievements are as follows:(1)Through the theoretical analysis method,the formula of stress and energy change caused by the change of coal seam thickness is deduced,and the equivalent elastic modulus of coal and rock mass decreases with the increase of coal seam thickness,while the accumulated energy increases with the increase of coal seam thickness,increasing the risk of impact.(2)Established numerical simulation model to simulate coal thickness,coal seam dip angle,thickness of the bottom coal.The purpose of the study is to get the influence on the destruction rule of surrounding rock of roadway,the results show that the larger the thickness of coal seam,coal thickness change,the more intense the dip Angle of coal seam,the greater the purpose of the coal thickness,the greater the impact increased risk in coal roadway,the faster the speed of extraction,lower risk impact.(3)By applying dynamic load to the roof of roadway with different thickness of coal seam,the results show that,under the disturbance of the same dynamic load,the thicker the coal seam at the roadway location,the greater the velocity of the unit above the roadway,the greater the accumulated elastic strain energy,resulting in the increased risk of impact.(4)After the anti-impact and pressure relief measures were applied,the microseismic monitoring results showed that the maximum energy was reduced by68.23%,and the deformation values of the roof,two sides and floor were reduced by70.31%,76.75%and 79.64%,respectively,indicating that the anti-impact effect was significant.There are 99 figures,10 tables and 110 references in this paper.