Study on the characterization of surface crack structure of coal based on fractal theory

Based on the background of the 2 # coal seam mainly mined in Yulin Mining Area in northern Shaanxi, china, this paper uses the Scanning electron microscope test method, through the process of sample preparation drying testing analysis, uses the fractal theory and box counting method to analyze the fractal characteristics of surface fractures, obtains the number of fractures under different fractal scales, and uses the least square method to calculate the number of fractures N(δ)And grid edge length δ Through regression analysis, it was found that the analysis dimension of coal seam fractures in the main mining seam of Yulin mining area in northern Shaanxi is between 1.0115 and 1.5082, which can provide basic support for the later application of water injection dust reduction engineering.