Earthquake-induced environmental impacts for residential Italian buildings: Consequence models and risk assessment

Abstract

The growing interest in built environment sustainability calls for integrating seismic risk into life cycle analyses of structures in earthquake-prone regions. To fulfil such need, this study develops consequence models that estimate the environmental impacts of repairing multiple seismic damage levels (or damage states, DSs) for typical structural/non-structural components of reinforced concrete (RC) buildings in Italy. These models, compatible with the FEMA P-58 risk analysis framework, are derived from empirical data on construction materials used in repair works. The environmental impacts are expressed in terms of embodied carbon, a metric of greenhouse gas emissions contributing to global warming (and climate change). The derived models are then adopted within the FEMA P-58 framework to conduct a risk assessment of earthquake-induced embodied carbon for nine archetype RC frames with different heights and design-code levels representing various building types within the residential building stock of Italy. This process requires analysing their nonlinear response under increasing ground-shaking intensities, evaluating damage in individual building components, and translating it to embodied carbon via the consequence models. This study also derives probability distributions of building-level (as opposed to component-level) damage-to-embodied carbon ratios, which link the global DSs sustained by the case-study frames to the corresponding normalised embodied carbon. These ratios are valuable in risk assessments of building portfolios as they enable rapid environmental-impact estimation, achieving a trade-off between accuracy and computational effort. Lastly, the correlation between embodied carbon and repair costs is investigated to explore practical simplifications of risk analyses when environmental-impact data are not available.