Application of High-Density Resistivity Method in the Detection of Coal Mine Goafs

Abstract

Aiming at the detection of coal mine goafs beneath transmission lines, this paper investigates the application of the high-density resistivity method using the Wenner array. Geoelectric models representing water-filled (low-resistivity) and non-water-filled (high-resistivity) goafs were constructed, followed by forward modeling and inversion analysis based on the least squares method. The simulation results indicate that this method accurately delineates the boundaries of high-resistivity anomalies. For low-resistivity anomalies, although the inverted depth shows slight thickening, the horizontal location and overall extent are reliably identified. In engineering practice, the inversion profiles of four survey lines revealed distinct low-resistivity anomalies, and the inferred goaf locations were basically consistent with subsequent geotechnical investigation data. This study confirms the effectiveness of the high-density resistivity method (Wenner array) in goaf detection, providing a scientific basis for the site selection and stability evaluation of transmission line projects.