STUDY OF REASONABLE WORKING RESISTANCE OF SUPPORT IN FULLY-MECHANIZED SUBLEVEL CAVING FACE IN EXTRA-THICK COAL SEAM

By using microseismic monitoring technology,similar material simulation test and macro observation of support resistance in project site,the reasonable working resistance of hydraulic support is studied.Macro observation of support resistances shows that the support resistances under normal circumstance and abnormal circumstance(the main roof strata pressure) are 9 000–12 000 kN/frame and 13 000 kN/frame respectively.Similar material simulation test shows that the resaonable working resistances of support are 9 000–12 000 kN/frame under normal circumstance and in the case of the lower main roof pressure and the higher main roof pressure those are 13 000–15 000 kN/frame and 17 500–23 000 kN/frame respectively.Microseismic monitoring results show that the support resistance under normal circumstance is 10 971.45 kN/frame on average,and that under abnormal pressure is greater than 13 333.95 kN/frame.Hydraulic support working resistance is obtained through the similar material simulation test.Comparative study among similar material simulation experimentf,ield macro observation and microseismic monitoring shows that the working state of support can be divided into three categories,i.e.normal state,low roof strata pressure and high roof strata pressure.