Implication of Electrical Resistivity Tomography for Precise Demarcation of Pothole Subsidence Potential Zone Over Shallow Depth Coal Mine Workings

Abstract

Abstract Pothole, an undesirable catastrophic consequence, is a common phenomenon in old coal mine workings, especially at shallow depth endangering habitats and surface structures. Precise identification of pothole potential zone is vital to prevent any major setbacks. Limited sub-surface information leads to branching out from the realistic ground conditions resulting in improper inferences. Resistivity imaging system is a favourable tool for gathering and strengthening technical information to demarcate the potential areas of pothole occurrence as it has proven ability to translate the characteristic of strata. Geological disturbance, one of the causes for pothole, has been located precisely by electrical resistivity survey at the study site. The overlying rock type has been correlated with resistivity range and validated with borehole lithology. Considering influencing parameters for pothole i.e. position of underground workings, geological disturbance and nature of near surface strata potential locations of the pothole likely to occur has been demarcated based on resistivity characteristics. Two potholes occurred in the past also helped in strengthening in interpretation.