Assessment of Post-Earthquake Damaged Building with Interferometric Real Aperture Radar

Ramon Gonzalez-Drigo,Luis Pujades,Yeudy Vargas-Alzate,Jorge Avila-Haro,Guido Luzi,Esteban Cabrera

doi:10.3390/rs11232830

Abstract

In this study the main results of a detailed analysis of an actual building, which was severely damaged during the Mw 5.1, May 11th 2011, Lorca earthquake (Murcia, Spain) are presented. The dynamic behavior of the building was analyzed by means of empirical and numerical approaches. The displacement response of the building submitted to ambient noise was recorded by using a Real Aperture Radar (RAR). This approach provides a secure remote sensing procedure that does not require entering the building. Based on the blueprints and other available graphical information about the building, a numeric 3D model was also set up, allowing obtaining capacity spectra and fragility curves in the two main resistant directions of the building. The main purpose of this study was to check out the feasibility of the RAR-based method to detect the safety state of a damaged building after an earthquake, without the need of entering unsafe structures. A good consistency of the numerical and experimental approaches and the observed damage was obtained, showing that RAR interferometric-based tools may provide promising supplementary remote sensing methods to safely survey and report about the structural health and the operative conditions of buildings in post-earthquake scenarios.

Highlights

On May 11, 2011, a moderate, 5.1 Mw, earthquake occurred in Lorca, (Murcia, southeast Spain)
The amplitude peaks detected at different times correspond to contributions from parts of the observed structure located at different distances
Remote sensing was performed by using a RAR device because the interferometric technology is capable of managing high frequency dynamic measurements with high resolution

Summary

Introduction

On May 11, 2011, a moderate, 5.1 Mw, earthquake occurred in Lorca, (Murcia, southeast Spain). Despite the rather low magnitude and macroseismic intensity (VII in the European Macroseismic EMS’98 scale) of the earthquake, significant damages and nine fatalities were reported. Buildings in the San Fernando neighborhood suffered various damage grades. Significant differences among damaged nearby buildings have been attributed to directionality effects of the strong ground motions [2,3]. The main purpose of this study is to analyze the feasibility of using advanced high-resolution remote sensing devices to know about the safety state of a damaged building. To this end, a reinforced concrete building of the neighborhood, which was severely damaged by the earthquake, and a Real

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