Life-cycle probabilistic seismic risk assessment of high-rise buildings considering carbonation induced deterioration

The geometrical and mechanical properties of reinforcing steels embedded in the RC structures may be deteriorated due to the aggressive environments, such as the carbonation, chloride, and wind-induced fatigue. The joint effects of aging and seismic load on the response of high-rise buildings are always neglected in current structural design specifications. This paper presents a probabilistic methodology to assess the time-dependent annual damage probability considering the carbonation-induced corrosion and the uncertainties associated with random variables under seismic excitations, which is implemented in a 42-story steel frame-RC core tube building. The loss of cross-sectional area and reduction in strength of reinforcements are considered in the analysis for the serviceability and safety limit states. The seismic hazard model and conditional fragility are integrated to compute the total annual damage probability of this building at different aging scenarios. Numerical results indicate that the carbonation-induced corrosion in reinforcements has significant impacts on the structural performances during its lifetime under both the serviceability and safety limit states. Neglecting the influences of deterioration may lead to erroneous predictions of damage probabilities for corroded high-rise buildings. The application of this study highlights the necessity of comprehensively discussing the detrimental effects of harsh environments on high-rise buildings, which may be neglected in the available literature.