Research On Mining Influence Analysis And Pressure Control Technology Of Through-Graben Structure In Fully Mechanized Caving Face

Graben structure is a geological structure formed by the combination of two faults.Compared with a single fault,the interaction mechanism between two faults in graben structure has a greater impact on the safety of coal mining.In order to make clear the adverse mining influence caused by graben structure,this paper studies the mining influence analysis and ore pressure control technology of fully mechanized caving face through graben structure by adopting the method of similarity simulation test,numerical simulation and field measurement.The main research conclusions are as follows:(1)Similar simulation tests show that when the work is advancing towards the graben structure,the FL37 fault in the graben structure obstructs the stress transfer.At20 m away from the fault,the FL37 fault slips and instable under the influence of mining.When the working face advances through the graben structure,because of the inverted trapezoidal structure of overlying strata in the graben structure area,the roof overhanging,should be pre-treated in time.(2)Numerical simulation shows that,under the coupling of lateral mining stress in goaf,advanced abutment pressure of working face and original tectonic stress near graben structure,the stress of fully mechanized caving face during the graben structure is mainly concentrated in front of the upper roadway side working face.At the same time,the accumulation of elastic energy appears in the coal body at FL37 and FL39 fault in the upper and lower roadway,which is easy to induce dynamic disaster.The elastic energy value is successively the coal pillar wall,solid wall and deep part of solid wall(50m)from high to low.(3)The collaborative pressure relief control technology of roof pre-split blasting,roof cutting and pressure relief and large diameter drilling is put forward to cut off the overhanging roof of the working face,prevent the dynamic disaster caused by sudden roof collapse,and reduce the advance coal rock pressure of the working face.The numerical simulation results show that the stress value in front of the working face is reduced by 2.22-9.96 mpa after collaborative pressure relief,and the elastic energy value accumulated in coal mass at FL37 and FL39 faults in upper and lower roadway is reduced by 15.27% to 43.61%.(4)The coordinated pressure relief control technology of roof pre-splitting blasting and large-diameter drilling was implemented in 6305 working face,and the ore pressure monitoring scheme of fully mechanized caving working face under graben structure was proposed.The measured data show that the ore pressure of the working face is effectively controlled and can meet the needs of safe production.Figure 70 Table 6 Reference 90...