Integrated seismic vulnerability assessment of road network in complex built environment toward more resilient cities

The road network is recognized as an important infrastructure system that is playing an essential role in making cities more sustainable and resilient. Hence, it is crucial to increase the safety and resiliency of urban road networks against external shocks such as earthquakes, by ensuring that they function efficiently within the complex-built environment systems in that they reside. Previous research on disaster risk management for road networks focused mainly on the assessment of the physical vulnerability for one criterion, without considering multiple vulnerability criteria of the road infrastructure and its interaction with the built environment. The primary goal of this research is to present an integrated vulnerability assessment approach based on intrinsic and eccentric characteristics of road networks. The proposed method employs two Vulnerability Indexes (VI); the first one assesses the Intrinsic Seismic Vulnerability (ISVI) of the network that considers the direct physical damage of the roadway system, while the second one, is the Eccentric Seismic Vulnerability (ESVI) that is based on the damage of the surrounding damaged buildings surrounding the roads. Subsequently, the correlation between the assessed indexes is utilized to provide a more holistic assessment tool in support of emergency and evacuation plans during earthquake incidents. These indexes are applied to assess the accessibility to emergency critical service centres based on a territorial framework for an urban area. The methodology and case study show the importance of the integrated seismic vulnerability assessment in the resilience of critical city infrastructure, for enhancing emergency access and implementing effective risk mitigation measures.