Damage assessment of structural and geotechnical damages in Kahramanmaraş during the February 6, 2023 earthquakes

Two major earthquakes occurred in Pazarcık and Elbistan, Kahramanmaraş on February 6, 2023. The first earthquake recorded at 04:17 local time had a magnitude of Mw = 7.7 with a focal depth of 8.6 km. The second earthquake occurred at 13:24 local time with a magnitude of Mw = 7.6 with a focal depth of 7 km. Many buildings were severely damaged and failed in these earthquakes. It caused an estimated $100 billion in economic losses and more than 50,000 deaths. This article aims to examine the acceleration records, acceleration response spectra, and the seismological characteristics of Kahramanmaraş earthquakes. In this study, the causes and conditions of structural, geotechnical damages are presented from observational studies conducted after the two earthquakes. According to data received from MEU (Turkey Ministry of Environment and Urbanisation), that approximately 57 % of the buildings in Kahramanmaraş were damaged. It can be seen that the most heavily damaged buildings are concentrated in the Dulkadiroğlu, Onikişubat and Göksun districts. The soft/ weak story, weak beam-strong column philosophy, lack of shear walls, low quality of construction workmanship, low concrete and steel grades, and poor ground conditions are determined as the significant causes of the damages in the observational studies.