Seismic Capacity Assessment of Reinforced Concrete Buildings in the 2023 Turkey Earthquake: Relation of Base Shear Strength Coefficients and RC Wall Area Ratios to Damage and Comparison with Other Earthquake-Prone Countries

This study presents an analysis of 202 reinforced concrete (RC) buildings in Turkey affected by the 2023 earthquake, using concepts from the Japanese standard evaluation method. The focus is on the correlation between the base shear strength coefficient and observed damage. Comparative assessments of buildings affected by past earthquakes, including the 1995 Kobe, 2015 Nepal, 2016 Taiwan, and 2016 Ecuador events, indicate a strong relationship between structural damage and the base shear strength coefficient. The average coefficient for the Turkish buildings was estimated at approximately 0.2, while higher values approaching 0.4 were observed for buildings surveyed after the 1995 Kobe and 2016 Taiwan earthquakes, which reflect stiffness-focused design practices. Buildings with lower coefficients tended to experience more severe damage. In addition, a higher proportion of RC wall area, specifically 0.3 percent or more relative to the total floor area, was associated with a reduced likelihood of severe damage. The observed correlation between an increased base shear strength coefficient and reduced damage, not only in the 2023 Turkey earthquake but also in the past earthquakes investigated in this study, reflects a core principle of Japanese seismic design, which emphasizes stiffness and strength over ductility. This underscores the critical role of RC walls in enhancing seismic performance and reducing structural damage.