Seismic vulnerability assessment of ageing reinforced concrete structures under real mainshock-aftershock ground motions

Ageing structures located in moderate to high seismicity regions are exposed multiple natural stressors during their lifetime. Large earthquake events coupled with environmental aggressive agents increase the progressive failure probability of these structures. The accumulated damage main event might be exacerbated by its following aftershocks. This result catastrophic structures, and consequently, several socio-economic losses. Taking such deterioration mechanism into consideration, current study presents a framework assess vulnerability ageing Reinforced Concrete (RC) frames subject real Mainshock-Aftershock (MS-AS) ground motion sequences. Employing an advanced fibre-based finite element modelling technique, nonlinear static dynamic behaviour case-study RC frame various ages is simulated under 48 MS-AS record pairs. Quantifying corrosion-variant states, age-specific fragility curves developed for considered structure both single MS It was found that severely corroded most likely collapse before second comes up. Moreover, results show PGA ratio AS plays critical role seismic assessment highly corrosion-damaged frames.