Geophysical exploration of columns in historical heritage buildings

Columns are one of the most usual supporting structures in cultural heritage buildings. This work presents the study of different columns using ground-penetrating radar (GPR) combined with seismic tomography. These columns belong to a Gothic Cathedral and to a Modernista Building. In the first case, columns are constructed with regular ashlars. GPR provide images that could define the internal ashlar distribution and shape, and the possible existence of inner cracks. However, the images must be supported with additional information from a seismic survey that could provide evidences about the stone quality. In the second case, columns are built with irregular and fragmented clay bricks, and mortar. The internal irregular and complex structure causes complicate 2D images. However, 3D images provide valuable information about the condition of the internal tube and indicate the existence of irregular elements. Results present high correlation with seismic data. In conclusion, results provide information and 3D images defining damaged areas and inner structures. Also, comparing the different methods with the structural knowledge, it is possible to define potential and limits of non-destructive testing applied to these elements.