Use of ground penetrating radar (GPR), reflection seismic and electrical resistivity geophysical methods in detecting geological anomalies for the purposes of safety and exploration at underground and surface mines.

摘要

There are several methods that can be used to image the rock strata in-situ, ranging from optical tools to the simple ones such as a scrape bar. The main disadvantage of those methods is that they are limited to random sampling of the strata, which can lead to non-detection of voids and separations. A more continuous method of strata evaluation needs to be devised. Ground penetrating radar (GPR) is a non-destructive electromagnetic geophysical tool that can be used to map continuous spans of the subsurface. The GPR is not regularly used for detailed mapping of the roof strata in the past, because of the present belief that it lacks the required resolution to detect small rock discontinuities such as thin clay layers or the separation between bedding planes.; Findings of laboratory and field experiments show that the GPR, when using 1500 MHz a high-resolution and shallow-depth antenna, can be used for mapping the strata. This dissertation demonstrates that the GPR can be used as a mapping tool for evaluation of strata at limestone and dolomite mines, and the knowledge obtained by this tool could improve safety of mines and people who work there. The GPR data provides a structural image of the subsurface, which can be applied to define the mine roof span and roof support requirements at underground mines. It can also be used to assist in selection between ripping and blasting techniques for surface quarries.; Along with the evaluation of the GPR technique for mapping the rock strata, this project examines effectiveness of resistivity and reflection seismic techniques for detection of abandoned mine workings, buried objects, depth to bedrock, etc.