Subsoil geophysical evaluation using GPR and free software

In this work, a geophysical characterization of the subsoil of a civil structure corresponding to the basement of a residential complex in Bogotá, Colombia was carried out, using the GPR technique. We were chosen to establish the affectation caused by weeping willow (Salix Babylonica) trees planted near the retaining wall of the structure’s foundation and its parking lot platforms. We acquired GPR profiles all throughout the area of the internal part of the basement and the outer retaining wall part. The pieces of equipment used were SIR 4000 and a HS 350 MHz center frequency antenna. The data presented a good and consistent signal. High resolution subsoil images of up to 3m in depth of the area below the parking lots were generated through the analysis of information derived from the processing and interpretation of the data. All of these were compared with information from geotechnical and topographic studies of the area. The results obtained show that the trees’ roots are causing scour due to a drying effect of the subsoil, which caused damage to the slab in the parking lot and on the retaining wall.