Near-Real-Time Damage Estimation for Buildings Based on Strong-Motion Recordings: An Application to Target Areas in Northeastern Italy

Abstract

The rapid estimation of expected impacts in case of an earthquake is extremely important for emergency managers and first responders. Current near-real-time damage assessment methods rely on ground-motion estimates and exposure or fragility datasets, in some cases integrating the shaking recorded at the site (e.g., from strong-motion monitoring networks). We propose a method that estimates the expected damages on buildings based on strong-motion recordings of a seismic event. The damage assessment is based on the maximum drift (interstory) or the displacement, which is estimated by considering in a first approximation the behavior of a specific building typology as a single-degree-of-freedom oscillator. The oscillator is characterized based on the analysis of the building stock and a large number of ambient vibration measurements performed in buildings. A specific damage state occurs when the interstory drift or displacement limits available in the literature for the specific building typology are exceeded. The method, here applied to a case study in northeastern Italy, can be applied to other seismic areas worldwide to provide quick, first-level estimates of expected damages.

Estimation of Earthquake Early Warning Parameters for Eastern Gulf of Corinth and Western Attica Region (Greece). First Results

“…Finally, we note that further work is required in order to define the limitations [65] and uncertainties of a future EEWS as that of statistical independence of the displacement measurements at each station [23], the physical bounds of how accurately the strength of shaking can be estimated [22] along with appropriate metrics to validate the performance of an EEWS [23] contributing to the final goal of near real-time damage estimation [66].…”

Applying the damage assessment for rapid response approach to the august 24 M6 event of the seismic sequence in central Italy (2016)

“…Based solely on recordings at the bottom of buildings (or in the free field nearby), it is possible to rapidly estimate the occurrence of damage by taking the simplified buildings linear dynamic response into account (Scaini et al, 2021;Petrovic et al, 2022). In fact, the DARR (Damage Assessment for Rapid Response) method uses the entire recording and simulates the maximum relative displacement (drift) for a specific building type (defined by fundamental frequency and damping ratio) based on simplified oscillators (single or multi-degree-offreedom) using the Z transform (Lee, 1990;Jin et al, 2004;Parolai et al, 2015).…”

“…The DARR method can be extended to estimate expected damage to specific building typologies in the surrounding area of a recording (Scaini et al, 2021). In addition to interstory drift limits (e.g., Borzi et al, 2008;Rossetto et al, 2016), relative displacement limits (e.g., Lagomarsino and Giovinazzi, 2006) are available for different building types.…”

Regional based exposure models to account for local building typologies

“…Similarly, the presence of cobblestones, that can be found in historical centre built near rivers, can determine the presence of irregular masonry structures. In Italy, limestone can be found mainly in the internal Apennine areas, tuff is typical of volcanic areas and bricks are typical of the Adriatic coast and many northern towns, due to the large presence of alluvial deposits (Salmoiraghi 1892;Rodolico 1965;Zuccaro et al 1999). Thus, for example, the city of L'Aquila, in Abruzzi region, in which limestone is widespread, is characterized by the presence of irregular masonry buildings.…”

“…Examples of different masonry vertical structure types present in three Italian regions Photos reported in the table are adapted from the Reports of the damage caused by the major seismic events occurred in Italy in recent years, drafted by ReLUIS (Network of university laboratories for seismic engineering) and fromScaini et al 2021 …”