Identification of footwalls and roofs of coal seams in underground coal mines using borehole radar

In coal mining, the accurate determination of the locations of the footwalls and roofs of coal seams and the identification of the geological structures that threaten the safety of excavation are important measures to ensure safe coal mining. This study proposed a technique for detecting the footwalls and roofs of coal seams, which consisted of a mining face-based borehole radar detection method for underground coal mines and a data processing process. Then, this study applied this technique to the Xinyuan coal mine. Specifically, radar profiles were denoised and enhanced through the correction of zero-moment point, DC elimination, band-pass filtering, direct wave removal, and gain processing of measured borehole radar data of boreholes along a mining face of the Xinyuan coal mine. Then, the locations of the roofs and footwalls of coal seams in the underground coal mines were identified and presented through a series of processing and interpretation, including velocity pickup, reflective surface extraction, and diffraction stack migration, as well as time-depth conversion, flipping, splicing, and the correction of borehole trajectories. The technique proposed in this study serves as an effective means for the safe operation of coal mines and thus is of value for promotion.