FEBRUARY 2023 TÜRKİYE EARTHQUAKE SEQUENCE: AN EVALUATION ON STRUCTURAL DAMAGES OF REINFORCED CONCRETE STRUCTURES

A sequence of devastating earthquakes hit southeast Türkiye and north Syria in February 2023 causing thousands of casualties, injuries and catastrophic damages of the built environment. Kahramanmaraş Pazarcık Earthquake (M7.7), Kahramanmaraş Elbistan Earthquake (M7.6) and Hatay Earthquake (M6.4), causing strong ground motions with peak accelerations well over 1.0g, affected more than 11 cities in the region with a population around 14 million. There was a huge effort coordinated by the Ministry of Environment, Urbanization and Climate Change (MEUCC) to conduct structural damage assessments right after the earthquake. Damage assessment of more than 2 million buildings was completed within 60 days. Along with the staff of the Ministry, numerous engineers and architects were also enrolled in damage assessment voluntarily under the coordination of MEUCC. Thanks to the establishment of a standard damage evaluation method newly adopted, and widely conducted online and face-to-face trainings on this damage assessment methodology, damage assessors could generally conduct a reliable, objective and rapid assessment. In this paper, after a very brief description of the characteristics of the earthquake sequence and observed typical damages, evaluations are presented on the existing reinforced concrete (RC) structures mainly focusing on two common types of structures with distinctly different characteristics; the RC buildings constructed before and after the year 2000. This date represents a kind of milestone in construction practice in Türkiye due to lessons learnt after the severe earthquakes that hit the country in 1999. Based on the damage observations, several recommendations are made to avoid/reduce losses after future earthquakes in terms of design, construction, inspection and qualification of engineering services. Finally, the damage statistics and an evaluation of damage distributions for various types of buildings are discussed based on official damage data. While the current damage assessment system is believed to work sufficiently well for such a large-scale catastrophe, the potential improvement options are discussed considering an optimized solution in terms of safety, pace and economic considerations on the potential repair/strengthening/reconstruction interventions to be made afterwards.