The Features and Classification of Coal fractures in Major Coal Mining Areas of China
The natural fractures in coal are the main paths for mine gas flow. The features and development degree of coal fractures contribute directly to the seam permeability and coalbed methane drainage capacity. Hereby, the authors study the macro- and micro-features of the natural fractures in coal seam and its development rules, as well as the influence factors in major coal mining areas of China, and explore the real reasons affecting the seam permeability. The research discovers that the endogenetic fractures are regionally distributed, characterized by the consistency in the strikes in same mining area. The strikes for fractures are different in different basins. The strikes for fractures in major mining areas of China are described. The length and height of different fractures change dramatically, on which the fractures are classified into five types. According to the features of the fracture density and the connectivity, the fracture density is divided into 3 types, and the connectivity is divided into 3 classes; based on the combination relation, the development degree of the fractures is classified into four classes and nine types. The proposed classification unifies the criteria of coal fracture assessment.The development degree of fracture in coal is related to the coal-petrological component, lithology and coal metamorphism. The fracture density sequence from dense to sparse is vitrain, clarain and durain; from bright coal, semi-bright coal, semi-dull coal to dull coal. The fracture development in same coal lithotype but different coal seams also varies largely, and this regularity has the universality. From long-frame coal to coking coal, the density of main fractures in vitrain changes with the increasing coal metamorphism. At lean coal stage, the fracture density is decreased, but the regularity is unobvious thereafter.
fracture in coal feature classification influence factors
ZHONG Lingwen YUAN Zhengrong SONG Xiaozhong JIANG Wenping
Xian Branch of China Coal Research Institute, Xian City of Shaanxi Province, China,710054
国际会议
The 2007 International Symposium on Safety Science and Technology(2007采矿科学与安全技术国际学术会议)
河南焦作
英文
1541-1548
2007-04-17（万方平台首次上网日期，不代表论文的发表时间）