Detection and calculation of the height of water flowing fractured zone of coal roof in Binchang mining area

In the Binchang mining area,the rules of height of water flowing fractured zone formed by coal seam mining of coal roof are complex,and it is difficult to evaluate the impact of mine water hazards.In response to this problem,this paper analyzes the water inrush situation of typical coal mining faces and compares the difference of water inrush from working areas under different mining parameters.It is preliminarily obtained that the different mining lengths of different working areas have different influences on the water flowing fractured zone.Based on the field measurement,a comprehensive measurement method for the height of the water flowing fractured zone during the whole process of coal seam mining is summarized by "pre-mining exploration,mid-mining water level monitoring,and post-mining comprehensive testing".According to a large number of actual measurement results,it is recognized that the height of the water flowing fractured zone in Binchang mining area is controlled by the mining length.The water flowing fractured zone is large when the length is 175-240 m,and the water flowing fractured zone is small when the length is 80-151 m.When approaching,the height of the water flowing fractured zone increases nonlinearly with the mining thickness.According to the changing law of the height of the water flowing fractured zone,a nonlinear regression analysis method is used to fit the empirical formula to calculate the height of the water flowing fractured zone under two mining parameters,and the applicability of the formula is analyzed.The empirical formula obtained in this study is used to analyze the degree of influence of the Cretaceous Luohe formation aquifer on the newly mining face,which shows that the empirical formula can accurately evaluate the influence of the aquifer on the mining face,with an accuracy higher than the empirical formula recommended by the Handbook of Coal Mine Water Prevention and Control.The research is of great significance to the determination of the height of the water flowing fractured zone in the Binchang mining area and also other mines under similar conditions.Meanwhile,the research enriches the research results of the water flowing fractured zone in the roof of the Jurassic coal field in western China.