Study On Surrounding Rock Control Of 120502 Isolated Island Working Face In Liuzhuang Coal Mine

Aiming at the engineering geological conditions of 120502 isolated working face in Liuzhuang Coal Mine,this paper studies the stress field analysis of mining surrounding rock,the calculation of reasonable coal pillar width in roadway,the support design of two roadways in isolated working face and the actual measurement of the characteristics of rock pressure manifestation by comprehensive research methods such as numerical simulation,theoretical analysis and field measurement.Through numerical simulation,the stress field of surrounding rock of coal pillar is located in stress release area,the maximum value is 10.94 MPa,and the relative original rock stress is 14.75-15.98 MPa(calculated according to the average volume weight of 25KN/m3 and the buried depth is 590 m and 659 m according to the average value of wind tunnel).The stress concentration coefficient is 0.68-0.77 and the elastic stress is 14.75-15.98 MPa.Plastic balance calculation shows that the width of coal pillars in isolated island working face is at least 10.5 M.The stability of surrounding rock along 120502 track with 8 m width of coal pillars in lower side of 120501 belt conveyor is analyzed.Through the analysis of surrounding rock structure of gob-side drivage roadway with belt conveyor and track groove in 120502 working face,the influencing factors of roadway support stability are obtained,which provides a theoretical basis for successful application,and the comprehensive consideration principles of active support and coal pillar setting for gob-side drivage roadway in isolated island working face are put forward.Finally,through the theoretical calculation and the above research results,the support parameters of the two roadways are designed and the support strength is calculated.For the track along the trough section of 120502 working face passing through the fault and adjacent to the overlying area,the grouting reinforcement scheme is put forward,and the original separation closure after grouting reinforcement is obtained through borehole peering,the separation value is reduced to 10 mm,and there is no deep separation phenomenon,which is better.The safe and efficient mining of deep coal has been realized.Figure 17 Table 8 Reference 27...