| The dynamic damage and destruction characteristics of surrounding rock and the supporting technology of deep coal mine roadway have important engineering value and significance for ensuring the stability of roadway and preventing and controlling the dynamic disaster.In this paper,with the engineering background of a deep-buried dynamic disaster-type mine 401105 working face,laboratory test,theoretical analysis and computer numerical simulation are used to design the pressure relief support scheme for the roadway of the working face,and the monitoring,early warning and inspection support are made through the forecasting system.The main conclusions are:(1)The basic physical and mechanical parameters of coal and rock were obtained through laboratory tests;the influencing factors of surrounding rock stability in deep roadway and the mechanism of superimposed dead rock induced by dynamic and static loading were analyzed.(2)Analysis of the deformation and dynamic events of the surrounding rock under the original support scheme shows that the length of the roadway roof and the two anchor bolts is less than the loosening zone,which results in low strength and large deformation of the surrounding rock support of the roadway and can not effectively resist the occurrence instantaneously deformation caused by power failure.The support parameters were redesigned to increase the support strength.The length of the roof bolts was increased to 2500mm,and the distance between the top anchor cables was 1300mm×1800mm with the "4-5-4" type and the anchor bolt was changed to 3500mm.(3)The simulation results show that under the new support conditions,the surrounding rock deformation of the roadway is not large under the conditions of excavation,recovery and dynamic disturbance,but with the joint stress of the surrounding rock of the roadway and the high stress environment and the advance mining pressure,the stress concentration area and the peak value are larger.The elastic strain energy of the agglom,eration of surrounding rocks is also large,and dynamic disasters are easily generated under the action of dynamic disturbance.According to this,the three-dimensional strength-energy theory of dynamic instability of surrounding rock of roadway is proposed.The regional distribution with large m values mainly includes:in front of excavation head,two gangways,floor rock mass,and rock mass(including roof,floor,and two gangs)within the range of advance influence during mining,and these coal and rock masses need to be further developed to prevent the occurrence of dynamic disasters.(4)The principles and techniques for control of surrounding rocks in deep-disturbed roadways include:reducing the intensity of disturbances,strengthening supporting and improving support conditions,energy-absorbing support techniques,pressure relief techniques,setting weak structures,and suppressing anchor bolts(cables).Through the theoretical analysis,calculation and numerical simulation to determine the basic parameters of the roadway drilling pressure relief:pressure hole diameter of 113mm,hole spacing of 1.4m,the Ministry of pressure relief hole depth of 15m,floor pressure relief hole depth of 10m.(5)Design relief measures for roadway during roadway excavation and recovery.The excavation phase includes pre-dig borehole pressure relief,pre-blast blast pressure relief,bulk borehole pressure relief,bottomhole relief,and large intermediate hole diameter relief pressure;The pressure relief options in the recovery stage mainly include pre-splitting blast pressure relief of the roof and coal seam water injection.Various monitoring and early-warning indicators show that the surrounding rock in the working face and roadway is stable,the road is digging from to the end of mining,no power disaster occurs.This shows that the design of the roadway relief pressure support scheme is reasonable and feasible. |
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