Research on distribution and dynamic evolution characteristics of surface fractures in shallow coal seam mining of Shendong Mining Area

Abstract

The mining of shallow coal seams in Shendong Mining Area has resulted in well-developed surface fractures and complex three-dimensional air leakage. In order to study the distribution characteristics and dynamic evolution laws of surface fractures in Shendong Mining Area, take the shallow burial mining of Huojitu Well in Daliuta Coal Mine and Bulianta Coal Mine as the engineering background, a combination of on-site UAV fixed-point observation, infrared, geological radar and other technologies was used to study the distribution characteristics of macroscopic and hidden fractures on the surface, and to analyze the dynamic evolution laws of fractures. Research has shown that the goaf of the shallow coal seam mining face in Shendong Mining Area has a greater impact on surface strike fractures compared to inclined fractures. Among them, the effective influence range of 101 fissures in 12 lower 206 working face in Huojitu Well is 35 m, and 122 fissures in 22310 working face of Bulianta Coal Mine is 62 m. The maximum width of strike fissures is 80 cm, and dip fissures are generally less than 10 cm. The maximum width of strike fractures reaches 80 cm, and inclined fractures are generally below 10 cm; with the advance of the working surface, the width of the crack increases gradually until it is fully developed, and the spacing of the discontinuous section of the crack becomes larger and the drop increases. If the crack with a larger width (the crack width is greater than 10 cm) is close to the working face, the crack width will gradually shrink with the advance of the working face, and may even be closed.

Keywords

• shallow buried coal seam group
• surface fissure
• air leakage
• crack width
• dynamic evolution