Application of electrical resistivity imaging to detection of hidden geological structures in a single roadway

Abstract

Abstract Locating concealed geological structures in coal seams on both sides of a coal mine excavation roadway is of vital importance for safe production. Conventional electrical resistivity imaging methods mostly arrange observation systems on the roadway roof and floor, so they are inevitably deficient when it comes to detecting concealed geological structures in coal seams. According to the electric field distribution characteristics of artificial field sources for electrical resistivity imaging methods and utilizing the shielding of current by roadway cavities, this paper proposes the parallel coal seam detection method that arranges observation systems in coal seams on the roadway side to detect concealed geological structures in coal seams. On the basis of introducing the principles of consequent detection methods, this paper investigates the influence of roadway cavities on observation results and offers a method of correcting the influence of roadway cavities. In view of the geoelectric characteristics of typical concealed geological structures in working faces, this paper establishes numerical models to verify the feasibility of the parallel coal seam detection method. As indicated by the calculation results, the consequent pole–dipole (A-MN) observation system is the most ideal in terms of dividing the geoelectric interfaces of concealed geological structures in working faces, and its detection effect is influenced significantly by the coal seam thickness and the electric differences between surrounding rock and anomalous bodies. Coal seam resistivity slightly influences detection of the consequent pole–dipole system. According to practical application effects, the parallel coal seam detection method can solve the problem of detecting concealed geological structures in “single-roadway” working faces.