Seismic Loss Estimation for Chloride-Corroded Reinforced Concrete Structures in Urban Environments

Chloride-induced corrosion in reinforced concrete buildings can considerably reduce both their seismic performance and economic resilience. However, limited research has been devoted to integrating corrosion-induced deterioration into annual seismic loss estimation, particularly considering direct losses, indirect losses, and human losses in urban environments. This study develops a practical framework for estimating seismic losses in aging concrete structures, incorporating existing assessment guidelines. The expected annual loss (EAL) is estimated taking into account four structural limit states. Two buildings in Tianjin and Fuzhou, China, subject to differing seismic hazards, are analyzed to demonstrate the proposed method and assess regional seismic losses. A probabilistic modeling strategy is adopted to simulate chloride-induced corrosion and its impact on structural degradation. The results indicated that aging significantly increases seismic fragilities, with structures reaching 60 years experiencing EAL values up to 2.6 times higher than pristine buildings. Additionally, the site-specific seismicity substantially influenced the values of EAL. The EAL of Tianjin was up to nine times higher than that of Fuzhou due to its higher seismic hazard. This study also reveals that indirect losses can account for more than 60% of total economic losses, highlighting the necessity of incorporating indirect loss considerations into seismic loss estimation frameworks to improve the reliability of postearthquake economic impact predictions.