Lessons From the 2023 Southeast Türkiye Earthquakes: A Study on Damaged RC Buildings Considering the Hassan Index

Abstract

A survey was conducted across 10 cities in Southeast Türkiye to classify damage in 242 reinforced concrete (RC) buildings constructed in the last 15 years, ranging from 2 to 16 stories. The ‘robustness’ of these buildings was quantified using ratios of cross-sectional areas of vertical elements (walls and columns) to floor-plan areas. The results are compared with similar measures obtained for buildings in Erzincan and Duzce (Türkiye) and buildings in Chile and Japan as well. These comparisons suggest that excessive drift was one of the primary causes of the widespread damage in RC buildings across the cities surveyed, from Antakya to Malatya. Drift a) exposed a myriad of defects in structural layouts and reinforcing detailing, b) caused nearly destruction of partitions and other non-structural building components (leading to disruptions of functionality even in the absence of structural damage), and c) induced instability even in structures with better detailing. In contrast, stiff (albeit uncommon) structures with abundant and well-distributed structural walls had lower drifts and performed well. Except for sporadic failures in details placed at critical locations, those structures are still in use and should serve as models for reconstruction. © 2024, International Association for Earthquake Engineering. All rights reserved.