Advanced Video-Based Processing for Low-Cost Damage Assessment of Buildings under Seismic Loading in Shaking Table Tests

Abstract

This paper explores the potential of a low-cost, advanced video-based technique for the assessment of structural damage to buildings caused by seismic loading. A low-cost, high-speed video camera was utilized for the motion magnification processing of footage of a two-story reinforced-concrete frame building subjected to shaking table tests. The damage after seismic loading was estimated by analyzing the dynamic behavior (i.e., modal parameters) and the structural deformations of the building in magnified videos. The results using the motion magnification procedure were compared for validation of the method of the damage assessment obtained through analyses of conventional accelerometric sensors and high-precision optical markers tracked using a passive 3D motion capture system. In addition, 3D laser scanning to obtain an accurate survey of the building geometry before and after the seismic tests was carried out. In particular, accelerometric recordings were also processed and analyzed using several stationary and nonstationary signal processing techniques with the aim of analyzing the linear behavior of the undamaged structure and the nonlinear structural behavior during damaging shaking table tests. The proposed procedure based on the analysis of magnified videos provided an accurate estimate of the main modal frequency and the damage location through the analysis of the modal shapes, which were confirmed using advanced analyses of the accelerometric data. Consequently, the main novelty of the study was the highlighting of a simple procedure with high potential for the extraction and analysis of modal parameters, with a special focus on the analysis of the modal shape’s curvature, which provides accurate information on the location of the damage in a structure, while using a noncontact and low-cost method.

Seismic Fragility Curves of RC Buildings Subjected to Aging

“…The latter can be seen from the pushover curves, as discussed in the next subsection. Furthermore, several works that evaluate the changes in the dynamic characteristics can be found in the literature, e.g., Ditommaso et al [41] and Cataldo et al [42].…”

Dynamic Failure Experimental Study of a Gravity Dam Model on a Shaking Table and Analysis of Its Structural Dynamic Characteristics

“…Additionally, there are limited instances of high concrete gravity dams collapsing or failing directly due to seismic effects, and research on the failure mechanisms and damage patterns of high dams is not still comprehensive. Shaking table testing is an effective method for studying the nonlinear dynamic response and damage mechanisms of structures, providing validation and a meaningful supplement to theoretical analysis and numerical simulation calculations [ 16 , 17 ]. Conducting such tests is crucial for comprehensively understanding a dam’s dynamic response and failure modes under strong seismic action, providing the validation of the numerical analysis results, and offering effective support for the seismic design of dams.…”

Identifying Damage in Structures: Definition of Thresholds to Minimize False Alarms in SHM Systems

“…Iacovino et al [19] proposed a variation of the Curvature Evolution Method (CEM), aiming to reduce some uncertainties derived from the evaluation of modal parameters during a strong-motion earthquake. The CEM method for damage location was updated by Ditommaso et al [20] and successfully applied to a damaged structure [20,21], providing the possibility of also quantifying structural damage by defining empirical correlations between curvature variation and maximum inter-story drift (valid only for reinforced concrete framed structures). In recent years, the reduction in the cost of structural monitoring technologies has promoted their widespread adoption for both building and infrastructure monitoring.…”