Acquisition and processing of buildings’ vibrations using a Real-Aperture Radar, a non-invasive method

Abstract

In this paper, a simplified non-invasive method to diagnose the safety state of buildings is tested. The method is based in remote sensing measurements of the natural vibrations of actual buildings using an interferometric Real-Aperture Radar (RAR). This non-invasive technique may allow us to detect damage in buildings by means of the change in their modal properties, mainly the fundamental period, which is measured using ambient vibrations. To test the technique, a set of buildings located in Spain were measured by using the remote procedure and the results were compared with the ones obtained with conventional acceleration or velocity sensors. In this paper, the results a building of the campus of the Technical University of Catalonia (UPC) are shown. The fundamental period of the building was successfully obtained by means of remote and easy measurements. The method is more successful for mid-to high-rise buildings where the RAR shows a better performance. The final purpose of these studies is to check for the ability of such remote sensing surveys to detect damaged buildings. The technique may be very useful in post-earthquake inspections as the method may allow us to know the safe/unsafe state of buildings without entering them.