Search Results (2)

The caving method and mining disturbance may cause geological issues. The advance prediction of unfavorable geological bodies should be conducted to ensure product safety in the underground mine. In this study, we proposed the OCTEM-PHA analysis process and analyzed the Tongkeng Mine in Guangxi. Further, we conducted opposing-coil transient electromagnetic method (OCTEM) detection on four detection lines in T5-1 stope at mine level 386 by using portable geological remote sensing equipment and created inversion maps. Plot profiles and coupling were analyzed with inversion maps to explore the five types of risk factors presented in the mine. The preliminary hazard analysis (PHA) method was used for five types of risk factors to predict the accident consequence and develop safety countermeasures. The results indicate the following: (1) the OCTEM-PHA safety analysis process for unfavorable geological bodies is realistic and feasible. (2) OCTEM shows an excellent response to both high- and low-resistance anomalies in practical engineering applications. The coupling analysis of profiles and inversion maps helps visually analyze the area of apparent resistivity anomalies. (3) The studied mine did not show overhanging formed by the overlying rock layer and large loose void areas. However, the crumbling mining area should be further optimized for balanced mining, the treatment of groundwater and surface water should be improved, and the comparative analysis with the follow-up detection results should be increased. Full article

Leakage in the impervious layer of a domestic waste landfill seriously pollutes the soil and groundwater. Therefore, it is necessary to carry out rapid nondestructive leakage location detection. In this research, the electrical resistivity tomography (ERT) method and the opposing-coils transient electromagnetic method (OCTEM) were used to detect the leakage location. The inversion sections of both methods showed a clear low–middle–high resistivity spectrum in the longitudinal direction that could be used to speculate the distribution pattern of the upper waste body layer, the bottom impermeable layer, and the lower limestone layer. The leakage area was identified in Zone B of the landfill on the basis of inversion results and drilling verification results. The results indicate that OCTEM and ERT were both sensitive to leakage detection. However, OCTEM had higher longitudinal resolution and more refined inversion results, resulting in more effective delineation for the location of the damage and leakage of the impervious landfill layer, thereby providing a new technical basis for landfill leakage detection. Full article