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

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.

Dynamic Monitoring of a Mid-Rise Building by Real-Aperture Radar Interferometer: Advantages and Limitations

“…The sampling parameters can be adjusted with the provided software. More details on the use and specifications of the RAR used in this study can be found in [13,14].…”

“…A detailed description of the working principle of the RAR can be found in [13,14]. One main feature of the radar is that it can simultaneously capture the movement of different objects that are in the field of view (FOV) of the RAR antenna.…”

“…The expected precision is in the order of tens of micrometers, when good phase stability is achieved with high SNR. A detailed description of the working principle of the RAR can be found in [13,14].…”

“…As a result, buildings can remain unoccupied for long periods until a final decision regarding their structural safety can be properly made. Any increment of the time between an earthquake and the occupancy allowance The use of the RAR to determine the dynamic properties of buildings is a present and actual issue [12,13]. Remote RAR measurements have been widely and successfully used for monitoring large civil structures including bridges and towers [14][15][16][17][18], wind turbines [19,20], chimneys [21][22][23][24], and heritage and high-rise buildings [25][26][27][28].…”

Earthquakes Reconnaissance Data Sources, a Literature Review

“…This paper aims to identify state-of-the-art data sources for building damage assessment and serve as a guide to make more efficient data collection based on the experiences in the last years. Damage is understood as a change in the mechanical, material and/or geometric properties of a building, affecting its performance and behaviour [8]. Damage data is highly 'perishable' or ephemeral since damaged structures may be altered or removed during rescue or early recovery [9] activities [10] or modified by aftershocks.…”