In recent years, risk, resilience and sustainability of civil infrastructure systems during their life-cycle have become emergent issues. The focus of this special issue is to address the current state of research and the future directions related to the risk, resilience, sustainability and management of civil infrastructure systems subjected to natural hazards in a life-cycle context.
Wang, Zhang, Ellingwood, Guo, Mahmoud and Li proposed a probability-based approach to assess the damage and economic losses of residential buildings in a community subjected to tropical cyclones. The damage to the individual buildings was determined through fragility functions of tropical cyclones. It was found that the correlations between the wind fields and construction practices have a great impact on the overall economic losses. The losses resulting from the damage of individual buildings were determined in terms of mean and variance using an approximate closed-form approach.
Anwar, Dong and Li proposed a decision-making framework for selecting the ideal alternative for retrofit options considering risk, resilience, and sustainability. The multi-criteria decision-making framework utilized performance-based perspective to evaluate performance indicators in terms of cost, casualties, equivalent carbon emissions, embodied energy, and repair time. An assembly-based approach was utilized to evaluate the damage of the buildings over a wide range of hazard scenarios in a life-cycle context. The proposed approach can be utilized to assess social, economic, and environmental consequences under seismic hazard and for the decision-making by considering the risk attitudes of stakeholders.
Osawa and Honda introduced a novel risk assessment methodology considering the dynamic characteristics related to maintenance planning under low-probability high-consequence events. To consider the probability of occurrence associated with rare events, suitable indices (e.g., conditional value at risk) were utilized incorporating potential policy changes that may take place in the future. The considered samples were divided into clusters to identify the low-probability high-consequence samples, since the use of Monte Carlo simulations in the iterated risk measure is computationally expensive. The proposed method considered also time-consistency and can be used to assess the effectiveness of the maintenance policy under extreme events.
Shoji and Honda revisited the commonly used assumptions for determining damage measures of peripheral lifeline systems. The examined lifeline systems consisted of buried water and sewage pipelines, as well as electrical and power distribution equipment. The main objective was to investigate the phase transition of infrastructure damage from moderate to extreme damage conditions. The authors also presented the preventive measures to counteract the transition to higher damage condition. The damages to the lifeline systems were investigated using statistical damage data from the 2011 Tohoku earthquake.
Ishibashi, Akiyama, Frangopol, Koshimura, Kojima and Nanami proposed a risk and resilience framework for road networks under earthquake-tsunami multi-hazard scenarios. Risk was evaluated in terms of economic losses, while resilience was assessed by determining the functionality of road networks. The reduction in tsunami capacity was determined based on the ground motion-induced damage. The damage arising from the tsunami hazard was assessed using structural vulnerability model. The proposed framework was illustrated for two Japanese cities given the occurrence of Nankai Trough earthquake. The study also presented retrofit prioritization based on risk and resilience.
Messore, Capacci and Biondini proposed a life-cycle cost and risk assessment framework for a spatially distributed bridge network under different deterioration scenarios. The framework was illustrated on a road network in the Lombardy region in Italy, where the seismicity is quite low; nonetheless, the network seismic risk was exacerbated by the impact of environmental deterioration. The need for the life-cycle performance-informed management of infrastructure systems was then highlighted.
Roohi, van de Lindt, Rosenheim, Hu and Cutler investigated the effect of building inventory on the overall resilience-informed decision-making process. The authors considered physical infrastructure recovery as well as socio-economic metrics to evaluate resilience. The damage and functionality were assessed on a building-level and a general equilibrium model was utilized to evaluate the economic impact. The population dislocation model was then utilized to assess the social impact. The physical, economical, and socio-demographics resilience indicators were illustrated on Memphis Tennessee under seismic hazard to demonstrate the applicability of the proposed approach.
Sun, Bocchini and Davison proposed a policy-based decision model for improving resilience of infrastructure systems under various hazard effects. The model developed recovery sequence by considering uncertainties and complex interdependencies among infrastructure systems. The proposed model considered four restoration-related interdependencies, that are resource-sharing, precedence, functionality, and restoration delay due to service disruption. The methodology was illustrated on three physical infrastructure systems: power, communication and transportation systems in the Lehigh Valley, Pennsylvania.
Ryan and Stewart aimed to address the suitability of climate adaptation strategy for five regions of Australia by utilizing probabilistic approach. Utilizing a performance-based method, the network maintenance practices were found to vary considerably for different regions. In particular, the adopted cost-to-benefit ratios varied from positive to negative for different regions indicating the difficulty of applying single adaptation strategy throughout the nation. This highlighted the need for region-specific climate adaptation policies to ensure positive cost-to-benefit strategies.
The Guest Editors would like to thank all authors and reviewers for their significant contributions. They hope that this special issue will serve as a valuable reference to all concerned with risk-, resilience-, and sustainability-informed assessment and management of civil infrastructure in a life-cycle context, including students, researchers and engineers form all areas of civil infrastructure systems.
The Hong Kong Polytechnic University, Hong Kong, China
[email protected]
Mitsuyoshi Akiyama
Waseda University, Tokyo, Japan
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Dan M. Frangopol
Lehigh University, Bethlehem, PA, USA
[email protected]
Yiannis Tsompanakis
Technical University of Crete, Chania, Greece
[email protected]