GPR backscattering applied to urban shallow geology: GPR application in seismic microzonation

This paper describes the application of ground penetrating radar (GPR) in the study of the shallow geology of urban environments, applying the survey in Barcelona city. The objective is to determine the existence of clusters of granular materials that could be related to paleochannles or subterranean streams. The method proposed for this study is to evaluate the signal to noise ratio (SNR) in radar data, caused by the backscattered energy as consequence of small targets. Laboratory tests and previous works indicate that variations of the SNR allow the detection of these sedimentary structures. The results will be used in the design of a detailed grid of points where soil vibrations must be measured. The combined methodologies allowed the construction of precise seismic microzonation maps of the city.