Radar Interferometer Application for Remote Deflection Measurements of a Slender Masonry Chimney
Seismic vulnerability of many cultural heritage masonry structures has been vital the recent years especially in seismic prone countries such as Italy. Due to the frequency of the seismic motions in time and due to many limitations, concerning the available knowledge and the seismic design of these stiff masonry structures, there is the necessity of non-contact and quick ambient response recordings so as to provide a structural integrity assessment. In order to improve the knowledge about the dynamic behavior of the slender masonry structures two main different analyses are necessary. The first goal is a territorial level assessment for the determination of the seismic ground motion. The second one concerns the knowledge of the dynamic characteristic of the existing structures. Recently, radar technique has been advanced by the development of microwave interferometers which serve non-contact vibration monitoring of large structures. The main characteristic of these radar systems, is the possibility of simultaneously measuring the dynamic deflection of many points on large structures. As a result, ambient vibration measurements can provide the identification of the modal properties of a structure. This paper reports a set of on-site applications of radar interferometer technique, aiming at evaluating the capability of measuring the vibration response of a slender masonry chimney in the Leonardo campus of the Politecnico di Milano. The results of the investigation highlight the accuracy and the simplicity of the technique for fast dynamic response measurements as well as the capability to detect temperature effects on the fundamental frequencies on the structure.
KeywordsAmbient vibration testing Radar interferometer Modal parameters Masonry chimney Territorial level analysis
The Research Fund - Flanders (FWO) is acknowledged for funding the two months research stay in Politecnico di Milano in the Department of Architecture, Built environment and Construction engineering (DABC), (V419718 N), and the first author G.L. acknowledges FWO, for funding the four years project “AE-FracMasS: advanced Acoustic Emission analysis for Fracture mode identification in Masonry Structures” (G.0C38.15).
- 1.Henderson, F.M., Lewis, A.J.: Manual of Remote Sensing, Principles and Applications of Imaging Radar, vol. 2. Wiley, Hoboken (1998)Google Scholar
- 2.Wehner, D.R.: High Resolution Radar, 2nd edn. Artech House Inc., Norwood (1995)Google Scholar
- 3.Taylor, J.D., McEwan, T.E.: The micropower impulse radar. In: Ultra-Wideband Radar Technology, pp. 155–164 (2001)Google Scholar
- 8.Stabile, T.A., Perrone, A., Gallipoli, M.R., Ditommaso, R., Ponzo, F.C.: Dynamic survey of the Musmeci bridge by joint application of ground-based microwave radar interferometry and ambient noise standard spectral ratio techniques. IEEE Geosci. Remote Sens. Lett. 10, 870–874 (2013)CrossRefGoogle Scholar
- 14.Gentile, C., Saisi, A.: Radar-based vibration measurement on historic masonry towers. In: Emerging Technologies in Non-Destructive Testing V, p. 51 (2012)Google Scholar
- 17.Breyman, G.A.: Trattato generale di costruzioni civili, voi I L. Cattaneo, L’arte Min atoria, Milano, Vallardi. 188 (1925)Google Scholar
- 18.Gouilly, A.: Théorie sur la stabilité des hautes cheminees en maçonnerie, par Al. Gouilly. J. Dejey (1876)Google Scholar
- 19.Skolnik Merrill, I.: Radar Handbook. McGraw-Hill Publishing Co. Ltd, New York (1990)Google Scholar
- 21.Luzi, G., Monserrat, O., Crosetto, M.: Real Aperture Radar interferometry as a tool for buildings vibration monitoring: limits and potentials from an experimental study. In: AIP Conference Proceedings, pp. 309–317 (2012)Google Scholar
- 22.Coppi, F., Gentile, C., Paolo Ricci, P.: A software tool for processing the displacement time series extracted from raw radar data. In: AIP Conference Proceedings, pp. 190–201 (2010)Google Scholar