Seismic damage scenarios for the Historic City Center of Leiria, Portugal: Analysis of the impact of different seismic retrofitting strategies on emergency planning

Abstract

As a result of several impactful events, the focus of the international community on the effects of natural hazards in urban areas has been increasing in recent years. The framework for research and innovation on urban risk reduction and urban resilience is presently defined by several technical and societal challenges at different levels. In fact, urban risk is a very complex multi-dimensional matrix that can involve multiple elements at risk, multiple hazards, multiple temporal scales, and multiple sources of vulnerability. Understanding the impacts and interactions between these elements is an essential step towards the development of more effective risk reduction strategies, particularly in historical city centers, which, due to their characteristics, are even more demanding. Within this framework, the present paper takes advantage of a large-scale seismic vulnerability assessment method, specially developed to assess the vulnerability of masonry façade walls, to evaluate the vulnerability and to develop damage scenarios for the Historic City Center of Leiria. Based on these scenarios, obtained for the relevant seismic intensities of the region, a variety of probabilistic-based outputs related to emergency planning (inaccessible urban areas, isolated people, and possible evacuation routes) were generated and comprehensively discussed. Finally, the potential benefit resulting from the application of different seismic retrofitting strategies is also investigated, both in terms of expected damages and evacuation scenarios.