Electrical Tomography for Studies of the Inner Structure of Dumps (Open-pit “Ellatzite”, Bulgaria)

The study presents the results of electrical tomography profiling (electrical resistivity and induced polarization) on external dumps at the vicinity of the open pit “Ellatzite” for copper ore mining (Central Balkan Mountain area, Bulgaria). The aim of the performed geophysical works was a clarification of the dumps structure, because increased instability of the dumps slopes, visible as a surface rupturing on the artificial terrain. The study is of importance for the engineering designing and decisions for the dumps stability. In order for more detailed mapping of subsurface structures the method of electrical profiling using the advanced technical capabilities of the electrical tomography on the base of multi-electrode schemes was applied. Two presented cross-sections, both crossing at the best way the western dumps, because of their positioning perpendicularly to the artificial, secondary sliding structures, are very informative and can be used for finding the necessary approaches to stop the processes of gravitational destroying of the dumps.