KNAW – minisymposium ‘Aardbevingsbestendige woningen’ 24 maart 2020Ondanks absentie van het symposium door de Corona crisis is dit boekje samengesteld voor digitale verzending en het drukken van een papieren versie.
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''Ever increasing population in seismically active urban areas, aging building stock, and expansion of urbanization to previously agricultural lands with soft soil deposits render the protection of human lives against earthquake disasters extremely more difficult by the time. Although much effort is put in further improving the current seismic design practices for new buildings, recent earthquakes show us, again and again, that life losses occur in older and much more vulnerable structures. Finding those substandard, collapse-vulnerable buildings before a destructive earthquake is like finding a needle in a haystack. It is clear that the problem in hand cannot be addressed with the existing, and mostly old-fashioned tools anymore.This manuscript focuses on how the emerging technologies, such as Artificial Intelligence, image processing, and data sciences in general, can be implemented as useful tools for conducting an urban scale seismic risk assessment while estimating the risk for every individual building. A review of the available technologies is given for the exposure component. Furthermore, a novel method of estimating the vulnerability of individual buildings, based on autoregressive machine learning algorithms, is presented. The manuscript discusses that the technological advancement is mature enough to radically alter how the earthquake risk is estimated.''
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''On February 6th, 2023, two severe earthquakes struck southeastern Türkiye near the Syrian border. The first earthquake, Mw7.8, occurred at 04:17 local time in the East Anatolian Fault Zone near the city of Gaziantep. The second earthquake, Mw7.5, occurred approximately 9 h later at 13:24 local time near Elbistan County, in Kahramanmaraş province. These seismic events ruptured multiple segments of the East Anatolian Fault Zone (EAFZ), with rupture lengths exceeding 300 km, and deformation exceeding 5 m on both sides of the faults. In this study, we aim to analyze characteristics of the strong ground motion induced by the mainshocks, focusing on ground motion intensity measures such as the peak ground acceleration (PGA), the peak ground velocity (PGV), and the pseudo-acceleration response spectra (PSA). The first earthquake produced extremely high PGA values in both horizontal (> 2 g) and vertical (> 1 g) components. At near field distances, large PGVs are measured (> 180 cm/s) with more than 30 impulsive motions which may indicate source-related effects. Large spectral demands are also recorded for both earthquakes, partially underestimated by Ground Motion Models (GMMs), especially in the near-field. Specifically, we compare the PSA for horizontal directions with the design spectra provided by both the new and previous Turkish building codes. We also present building and ground damage observations that provide insights into the observed ground motions in the heavily damaged areas.''
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