The ground penetrating radar As a tool for planning the exploitation of the candoglia marble quarry

Abstract

In the geophysics world, the Ground Penetrating Radar is an instrument every day more known and used, due to its easy implementation and methodology, short acquisition times and good results; the main application fields are archeology, the construction industry, geology, mining, among others. The present thesis work mainly consisted in the acquisition, processing and interpretation of GPR data in the Pink Marble Quarry of Candoglia, which is the main source of marble for the reconstruction of the Cathedral of Milan, the main historic structure of the mentioned city. The data acquisition process consisted in 7 different surveys in 5 areas, both on the floor and on the walls of the quarry, with 200MHz and 900MHz antennas, with the aim of finding contacts between the marble and the adjacent rock and/or fractures that could compromise the excavation that will be carried out in the future. Regarding the adjacent rock, the information obtained in the lateral wall was not very useful, because the minimum contact distance for structural reasons should be 5m, and the radargrams show very superficial information, between 1m and 2m. A Matlab code was made with the aim of being able to handle the data more freely, hoping to retrieve information in depth, obtaining unpleasant results. The main and useful information obtained consist in different 3D cubes, which were constructed from the interpolation of the 2D lines, showing some possible dip-slope direction fractures at a moderate depth, which would be of interest to the next excavation stage.