Research on the selecting type of the support in the condition of fully mechanized top coal caving and caving law of hard roof

Hard roof collapse has a certain impact on the hydraulic support.For the purpose of study Jizhong Energy Resources co.,LTD East Mine of Gequan Coal Mine 1197 coal mining face daqing limestone roof falling regulation and control in the condition of caving prone mining,the mechanical analysis of four-column hydraulic support was conducted on.The results show that:the after column of four-column hydraulic support easily was in tensile condition and it's not conducive to the roof caving mining prone control,two-column hydraulic support are more appropriate.The fractured situation of the daqing limestone roof was detected by YTJ20 rock Detection Recorder,the observations indicate:roof fractures are developed.Hydraulic stope support resistance show that selection of ZF3200/26/16 two-column hydraulic support are appropriate.Although the daqing limestone is relatively hard,but the roof could collapse with the exploitation,roof overhang is almost non-existent,roof does not require processing.