Empirical fragility assessment of low-rise hybrid buildings following the 2023 Kahramanmaraş earthquake sequence
Bulletin of Earthquake Engineering, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10518-026-02689-1
- Dergi Adı: Bulletin of Earthquake Engineering
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, Geobase, INSPEC, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Earth, Atmospheric, & Aquatic Science Collection (ProQuest), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Empirical fragility, Hybrid buildings, Kahramanmaraş earthquakes, Maximum-envelope Sa(0.3 s), Rapid visual screening, Seismic vulnerability
- Ankara Yıldırım Beyazıt Üniversitesi Adresli: Evet
Özet
This study empirically evaluates the seismic vulnerability of low-rise hybrid/semi-frame structures located in the Antakya and Nurdağı regions following the February 6, 2023, Kahramanmaraş earthquake sequence. This group falls outside traditional reinforced concrete or masonry classifications, representing an intermediate typology in which reinforced concrete frame elements and masonry walls act together with complex load transfer and stiffness distribution. For 169 1–3-story hybrid buildings filtered from official field damage assessment data, coordinate-based short-period spectral acceleration values were derived from USGS ShakeMap Sa(0.3 s) rasters of the Pazarcık and Elbistan main shocks, and the larger of the two values was adopted as the building-based maximum envelope Sa(0.3 s) demand. Continuous empirical fragility functions based on binary logistic regression were developed for damage thresholds of DS1+ (slight-or-worse), DS2+ (moderate-or-worse), and DS3+ (heavy-or-worse), using the observed damage classes. Within the analyzed sample, 59.76% of the buildings were classified as heavily damaged, requiring urgent demolition, or collapsed. This sample-level proportion should not be interpreted as an estimate of the regional prevalence of severe damage because the representativeness of the source sample could not be established. According to the developed fragility models, the median Sa(0.3 s) values corresponding to a 50% probability of exceedance were calculated as 1.238 g, 1.405 g, and 1.490 g for the DS1+, DS2+, and DS3 + thresholds, respectively. It should be noted, however, that the relationship for the DS1 + threshold exhibited only marginal statistical significance. The close proximity of these median values may indicate that damage in hybrid systems can rapidly progress from mild/moderate levels to heavy damage within a specific short-period demand range, although this trend may also partly reflect uncertainties in the dataset distribution and in the binary and rapid visual damage classifications. The findings provide preliminary empirical evidence that low-rise hybrid structures may not be adequately represented within conventional reinforced concrete or masonry categories in regional seismic risk assessments, and could instead be evaluated as a candidate separate vulnerability group that accounts for infill-wall–frame interaction, stiffness mismatch, and load-path discontinuities. Since these relationships are derived from a geographically concentrated dataset exposed to the specific ground motion characteristics of the 2023 sequence, they should be interpreted within this regional and event-specific context and regarded as broad statistical indicators of relative vulnerability rather than precise predictive tools for individual building performance.