Resilience Modeling And Analysis Of Interdependent Infrastructure Systems Based On Co-simulation Technology

With the rapid growth in urbanization around the globe,modern cities increasingly face various risks of natural and man-made disasters which pose serious threats to the safety of people and infrastructures.Infrastructure systems play a major role in sustaining urban functions,and thus,their disaster response capacity reflects the level of disaster preparedness of urban cities.Resilience provides an important new perspective for understanding the response of infrastructure systems throughout the lifecycle of disasters,and for assessing and enhancing the disaster response capacity of infrastructure systems.Studies on the resilience modeling of infrastructure systems are important for the assessment,diagnosis and enhancement of the resilience of infrastructure systems.However,most prior studies adopt highly abstracted monolithic models,which are inadequate for analyzing systemic heterogeneities and cross-system interdependencies,and are unable to simulate with sufficient granularity the intrinsic complexities of system operational mechanisms and interactions,demonstrating the inadequacy of existing resilience modeling methods.To address the above issues,this study assesses and clarifies the impact of systemic heterogeneities on the cascading failure of interdependent infrastructure systems,and proposes a co-simulation approach for modeling and assessing the resilience of interdependent infrastructure systems.The said approach captures various systemic heterogeneities by leveraging and integrating the domain-specific knowledge or models of different infrastructure systems.Specifically,this study begins by identifying various dimensions of systemic heterogeneity among infrastructure systems,and proceeds to develop an improved cascading failure model by incorporating the identified heterogeneities in a typical cascading failure simulation method.A case study is then conducted to evaluate the impact of heterogeneities on cascading failure,verify the need to consider heterogeneities in the modeling of cascading failure processes,and validate the proposed method.Next,to account for,and assess the impacts of,systemic heterogeneities,interdependencies and the dynamic impact of disasters on cascading failures,a modeling approach based on the co-simulation of domain-specific infrastructure system models is proposed.On this basis,this study further proposes a method to assess the interdependency effect on the cascading failure of infrastructure systems under different types of disruptions,and the proposed method is validated by means of a case study.Finally,based on the results of the cascading failure analysis,this study proposes a co-simulation method for the recovery process of interdependent infrastructure systems,that allows for detailed simulation of the impact of repair sequences on the state of the infrastructure systems.The simulation data is used to suggest an improvement criterion for the repair sequence decision model,and develop a genetic algorithm-based solution for optimizing the recovery of interdependent infrastructure systems.A case study is then conducted to verify the effectiveness of the recovery simulation and validate the proposed method.The resilience modeling and analysis methods proposed in this study can be used for disaster impact assessment,recovery decision making,optimization of interdependent system design,and comparison of recovery strategies.Moreover,the findings and deliverables of this study provide a strong foundation for the assessment,diagnosis and enhancement of the resilience of infrastructure systems.