Multipoint sources-based high-resolution electrical detection of the water-rich areas near mining faces of coal mine roadways

To accurately explore the spatial distribution of water-rich areas near mining faces of mine roadways, this study proposed a multipoint sources-based high-resolution electrical detection technology. A multi-channel electrode observation system was arranged behind a roadway mining face, with electrodes at a distance of 1/4 measuring lines behind the mining face as point source electrodes sequentially. Data were collected using a monopole-dipole device, with the obtained apparent resistivity considered the sounding data of multipoint sources-based electrical detection. The images of multipoint sources-based electrical sounding allow for quickly determining the presence of water-rich areas and their locations relative to the mining faces of mine roadways. Specifically, the detection range was divided into a series of target units. Then, the multipoint sources-based electrical sounding data were processed using the matched filtering method for abnormal targets, yielding the correlation imaging results of the detection range. Among them, the ranges of high correlation values can accurately reflect the distribution locations of rich-water areas in front of or behind the roadway heading mining faces. A theoretical template curve was obtained through the fitting of measured electrical sounding data. Subsequently, the multipoint sources-based sounding ratio data obtained using the ratio method can effectively eliminate the influence of factors such as roadway cavities and laminated strata. As indicated by the detection results of a mining face in the Pansan Mine of the Huainan Mining Group, the multipoint sources-based high-resolution electrical method can accurately detect the locations of water-rich areas near the mining faces of mine roadways, thus effectively guiding the prevention and control of water disasters during roadway tunning.