Seismic vulnerability of deficient RC buildings: insights from the February 6, 2023, Turkey earthquake

On February 6, 2023, two significant seismic events with moment magnitudes (M_w) of 7.8 and 7.5 struck southeastern Turkey and northern Syria, centered near Pazarcık and Elbistan in KahramanmarasProvince. These earthquakes affected over 15 million people and severely damaged reinforced concrete (RC) buildings across ten major cities, including Kahramanmaras, Hatay, Adıyaman, Diyarbakır, and Gaziantep, resulting in over 817,000 residential units either collapsed or heavily damaged. This study evaluates the seismic vulnerabilities highlighted by these earthquakes, focusing on structural deficiencies, such as inadequate shear reinforcement, poor beam-column joint detailing, insufficient confinement, and substandard construction practices. Additionally, geotechnical issues, particularly liquefaction and differential settlement, along with architectural irregularities, such as soft stories and short columns, significantly exacerbated structural failures. This research identifies critical gaps in construction code enforcement, professional training, and regulatory oversight, emphasizing the urgent need for enhanced seismic vulnerability assessments and more rigorous regulatory frameworks.