Reducing uncertainty in seismic assessment of multiple masonry buildings based on monitored demolitions

Abstract

A significant part of the existing building stock in regions of low to moderate seismic hazard has been designed without modern seismic considerations and is, in the meantime, exceeding its design life span. The assessment of seismic performance poses an engineering challenge, due to unknown material properties, undocumented structural interventions and the scarcity of event-based information. Operational modal analysis has been applied in some cases to verify model assumptions beyond visual inspection. However, masonry buildings exhibit amplitude-dependent stiffness even at very low response amplitudes, raising questions about the validity of such methods. Planned demolitions provide engineers with the opportunity to leverage higher-amplitude vibrations generated during demolition activities to better understand the dynamic behaviour of existing buildings. This paper introduces a Bayesian model-updating framework, which aims at reducing uncertainty in seismic analysis, by fusing dynamic measurements with best-practice structural models. The proposed hybrid framework is applied to nine real masonry buildings, representative of existing residential buildings, as typically encountered in Switzerland, that have been monitored during controlled demolition. A vast reduction in prediction uncertainty is achieved through data-driven model updating, additionally exposing intra- and inter-typological differences in terms of seismic capacity and ductility. In addition, differences between updated model predictions and typical engineering assumptions and generic typological curves are discussed. Overall, this contribution demonstrates, applies and discusses the practical benefits of a straightforward methodology for fusing monitoring data into the seismic evaluation of existing masonry structures.

Fusing damage-sensitive features and domain adaptation towards robust damage classification in real buildings

“…Following each ground motion, a low-amplitude white-noise (WN) excitation (with frequency content between 1 Hz and 40 Hz), with a root mean square (RMS) amplitude of 0.01 g is applied at the bottom of the structure. The selected frequency range covers the natural frequencies of low-and medium-rise masonry and concrete structures, which typically range from 2 Hz to 15 Hz [66]. This WN excitation simulates post-earthquake low-amplitude vibrations.…”

“…Including geometric configuration features (CFs) increases the predictive accuracy to 70% and 97% (soft accuracy). In a step further, characteristic structural properties (MFs per Table 4) that are possible to infer through model updating frameworks [66] are considered. Although significant computational effort is required for this task, the improvement in terms of accuracy is only marginal (Fig.…”

Seismic assessment of bridges through structural health monitoring: a state-of-the-art review

“…The information, which remains latent in the data, is often coupled with physics-based models, to update our knowledge of the as-is system, leading to updated numerical representations; also referred to as digital twins (Martakis et al. 2022 ). Alternatively, a purely data-driven approach may be followed for the extraction of condition/performance indicators (Noh et al.…”

“…In the context of SHM for seismic monitoring of bridges, dynamic response measurements, acquired through suitable sensor networks, are used to localize and quantify local damage and degradation of structural elements or antiseismic devices (Graham and Campbell 2013). Seismic monitoring of structures (Fujino et al 2019;Martakis et al 2019;Zhang et al 2023) in particular aims to (i) assess the seismic performance of bridge systems, (ii) identify bridge properties and compare these against design assumptions, and (iii) capitalize on gained knowledge to improve future designs and practices (An et al 2019;Rizzo and Enshaeian 2021).…”

Short-Training Damage Detection Method for Axially Loaded Beams Subject to Seasonal Thermal Variations

“…Indeed, during their normal operational conditions, temperature variations cause changes in the mechanical and geometrical properties of both the tie-rod and the structure, which reflects into changes of the axial load and, thus, of the dynamic response properties. However, at the same time, other tension variations are due to deformation and displacement of the connecting walls, that may be caused by terrain crawl, subsidence of foundations or seismic events [ 17 , 38 ].…”