A multi-scale framework for seismic loss assessment of urban areas

This study presents the ongoing activities – as a part of a wider research project – for the development of an innovative framework for assessing seismic risk and economic losses in urban areas. The proposed methodology employs a multi-scale approach: the urban area is idealized as a complex system composed of single assets (e.g., buildings, pipelines), organized into interconnected layers (e.g., building stock, roadways, and water distribution networks) that collectively define the urban system. Moreover, the approach involves multiple refinement levels of analysis for the estimation of both direct and indirect economic losses under different data availability scenarios. Alternative refinement levels include: (i) typology-based assessments, (ii) analytical or mechanical methods, and (iii) detailed numerical (software-based) simulations. Uncertainties associated with each level are quantified and propagated accordingly. Furthermore, the framework explicitly accounts for cascading effects and cross- layer interaction in the loss estimation. The proposed procedure is demonstrated through an illustrative application to a “virtual” urban area. The implementation of such a framework into a dynamic and updatable digital platform can potentially support risk- informed decision-making for the development and implementation of suitable seismic risk mitigation strategies, enhancing the safety and resilience of the community.