Abstract:
In order to quantitatively study the distribution and evolution characteristics of fault structure, and to reveal the control effect of fault structure on coal and gas outburst, the fracture system of Jiaozuo mining area was taken as the research object. The fractal characteristics of fault system in Jiaozuo mining area were analyzed by using single fractal theory. The fractal theory has carried out multi-fractal research on different regions. The single fractal and multi-fractal features were compared and analyzed. The multi-fractal spectrum was drawn and the multi-fractal characteristic parameters were extracted. According to the statistical law of the prominent accidents actually occurred in Jiaozuo mining area, the characteristic parameters and the prominent distribution law were compared. The results show that the fault system in Jiaozuo mining area has obvious fractal characteristics, and the fractal dimension reflects the complexity of the fault. The fractal dimension presents the zonal features, from the Fenghuangshan fault and the Yuhekou fault. It can be divided into three regions, and the fractal dimension of each fractal is consistent with the actual distribution pattern of the fault; the single fractal analysis can only reflect the complexity of faults, and fails to reflect the imbalance of coal and gas outburst distribution. The fault distribution in the Jiaozuo mining area has multiple fractal features, and the multifractal spectrum shapes of different regions have significant differences; the multi-fractal spectrum symmetry Δf and the spectral width Δα and other characteristic parameters comprehensively reflect the difference of tectonic setting, fault combination and motion mode. Symmetry Δf represents the number of large probability subsets and small probability subsets. It also characterizes the development degree of large and small faults. The spectral width Δα represents the degree of uneven distribution of the probability distribution of the fractal structure, and the degree of uniformity of the fault distribution is characterized.The multi-fractal representation of faults in different regions has inevitable gas geological reasons and spectral width. Δα has a good correspondence with the severity of gas outburst in each region; the multifractal characteristics of faults are closely related to the tectonic evolution process. By comparing and analyzing the multifractal features of faults in different regions, the evolution information of fault structures can be excavated, and the control effect of faults on the outburst can be further understood, so as to divide the risk of coal and gas outburst in mining area.