Impact of Near-Fault Rupture Directivity on the Seismic Performance of Existing Reinforced Concrete Buildings: A Probabilistic Seismic Hazard Analysis-Based Nonlinear Assessment

Near-fault ground motions influenced by rupture directivity impose seismic demands that differ fundamentally from those associated with conventional far-field earthquakes, particularly in terms of displacement-controlled response. This study presents a performance-based seismic assessment of existing reinforced concrete (RC) buildings subjected to near-fault ground motions in the Sivrice–Pütürge segment of the Malatya–Ovacık Fault Zone, Eastern Anatolia. A probabilistic seismic hazard analysis (PSHA) was performed using NGA-West2 ground-motion prediction equations together with a regionally defined fault model, and the resulting hazard was evaluated within the framework of the Turkish Building Earthquake Code (TBEC-2018). Code-compatible earthquake records were selected and scaled for the DD-2 design earthquake level, while rupture directivity was represented using a literature-based median amplification factor. Nonlinear time-history analyses were subsequently carried out for three existing RC buildings representing low-, mid-, and high-rise structural typologies. Structural performance was evaluated in terms of roof displacement, interstory drift ratio, base shear, and element-level damage states. The maximum roof displacements reached 0.070 m, 0.107 m, and 0.138 m for the low-, mid-, and high-rise buildings, respectively, corresponding to maximum drift ratios of 0.60%, 0.46%, and 0.34%. The results indicate that rupture directivity has only a limited influence on base shear demand but substantially increases displacement-related response quantities and promotes a redistribution of structural damage from predominantly beam-controlled behavior toward increased participation of columns and shear walls, particularly in medium- and high-rise buildings. These findings demonstrate that conventional code-based assessment procedures may underestimate deformation demands in fault-proximal regions and highlight the importance of explicitly considering rupture directivity in the seismic performance assessment of existing reinforced concrete buildings.