Analysis of the visible fracture system of coalseam in Chengzhuang Coalmine of Jincheng City,Shanxi Province

查看全文 作　　者：Shengwei [1]Wang;Guangjiu [1]Hou;Ming [1]Zhang;Qinping [1]Sun 机构地区：[1]China Univ Geosci, Fac Resources, Wuhan 430074, Peoples R China 出　　处：《Chinese Science Bulletin》索引2005年第50卷第S1期,共7页 摘　　要：In No. 3 coalseam of Chengzhuang Coalmine of Jincheng City, there exists the visible fracture system consisting of joints, gas-expanding fractures and cleats. The gas-expanding fractures develop mainly in the bright coal sub-layer and cleats, in the vitrain and bright coal. The joints fall into two types, one developing in the coalseam and the other cutting through the whole coalseam and entering into the top and bottom rock layer. The development direction of joints is basically similar to that of gas-expanding fractures: NNE and NNW. The formation of the visible fracture system is classified as the stage of the development of cleat fissures in the coalification period, the stage of the full development of cleats and the formation of gas-expanding fractures in the second coalification period and the stage of the formation of joints by structural function. There is the spatial unhomoge-neity in three dimensions for the visible fracture system of the coal seam in Chengzhuang Coalmine: the regular distribution of the visible fractures as groups in the plane and the coal sub-layer with high permeability rate in profile. The research findings of the visible fracture system of coal seam can be applied to the drilling of the coalbed methane and to heightening the let-off efficiency of coalseam gas. 关 键 词：the VISIBLE FRACTURE SYSTEM of coal SEAM development character origin coalbed permeability gas let-off of coalseam. DOI: 10.1360/98zk0008