Simulation-based consequence analysis of reinforced-concrete buildings subjected to earthquake- and environment-induced damage accumulation

Abstract

Structural systems in seismic-prone regions can experience sudden deterioration caused by earthquake-induced ground-motion sequences. In addition, given the prevailing environmental conditions at their site, these systems may undergo gradual deterioration resulting from environment-induced mechanisms. The combined impacts of such phenomena can result in significant structural/non-structural damage, leading to exacerbated consequences (e.g., repair costs, downtime, and casualties) during the systems’ service life compared to the consequences due to each phenomenon in isolation. Yet, such a multi-hazard threat is commonly overlooked. This paper proposes an end-to-end computational framework for simulation-based consequence analysis of deteriorating structural systems subjected to earthquake-induced ground-motion sequences and chloride-induced corrosion deterioration. State-dependent (and time-dependent) fragility and vulnerability relationships are derived as part of the proposed workflow. To this end, a multivariate probabilistic seismic demand model and a collapse generalised logistic model are developed, linking the dissipated hysteretic energy in the ground-motion sequence, the maximum inter-storey drift induced by the first ground motion, the intensity measure of the second ground motion, and the corrosion deterioration level. The time-varying corrosion rate is described through a hurdle model, employing an appropriate (continuous) chloride-penetration model. Vulnerability relationships are derived by combining the developed fragility relationships and suitable building-level consequence models. Finally, the (expected) life-cycle consequences are estimated by subjecting the system to stochastic event sets, encompassing ground-motion sequences. The proposed framework is demonstrated through a case-study reinforced concrete building. Considering the interaction between seismic sequences and corrosion effects, the expected life-cycle consequences in terms of economic loss ratio are 125 % higher than those without considering any hazard interaction. These consequences are mainly dominated by the effects of the ground-motion sequences rather than those associated with corrosion deterioration.