Geophysikalische Hohlraumerkundung am steirischen Erzberg
Research output: Research › Master's Thesis
In this study, several methods were deployed, to detect abandoned mining tunnels with 2,5m in diameter at around 20m of depth in the course of the project ZaB – Zentrum am Berg of the Chair of Subsurface Engineering of the Montanuniversität Leoben. Measurements with Ground Penetrating Radar, sensing of the total magnetic field, as well as electrical resistivity tomography were employed. The utilised Ground Penetrating Radar has 30MHz Antennas and a penetration depth of around 25m. A structure in medium depth was discovered, that could be, in good coverage with the results of geoelectrics and magnetics, a possible ore body. A clear localization of the searched mining tunnel could not be achieved with this method, thus the attempt is being made, to combine the findings obtained with the results of the other geophysical methods, to create a realistic model of the underground. In the same profile, multi electrode geoelectric measurements with 140 electrodes in Wenner configuration were performed, to obtain a picture of the resistivity variation of the subsurface by inversion. This shows at the suggested position an area with high resistivity that points out on the searched mining tunnel. One further zone of same kind was discovered at medium depth, which is also clearly perceptible with Ground Penetrating Radar. Furthermore, a geomagnetic prospection was performed, to detect possible iron containing installations like rails, rock bolts, wirings or similar. This method did not lead to the expected findings, because either are none or not enough of these structures present in the mining tunnel. Good correspondence could be found with geologically mapped lithologic borders, which provides good supplementary information for analysis of the other two methods.