Resilience assessment of interdependent infrastructure systems: With a focus on joint restoration modeling and analysis

As infrastructure systems are highly interconnected, it is crucial to analyze their resilience with the consideration of their interdependencies. This paper adapts an existing resilience assessment framework for single systems to interdependent systems and mainly focuses on modeling and resilience contribution analysis of multi-systems' joint restoration processes, which are seldom addressed in the literature. Taking interdependent power and gas systems in Houston, Texas, USA under hurricane hazards as an illustrative exmaple, five types of joint restoration stategies are proposed, including random restoration strategy RS₁, independent restoration strategy RS₂, power first and gas second restoration strategy RS₃, gas aimed restoration strategy RS₄, and power and gas compromised restoration strategy RS₅. Results show that under limited restoration resources, RS₁ produces the least resilience for both systems, RS₂ and RS₃ both generates the largest power system resilience while RS₄ is the best for the gas system; and if quantifying the total resilience as the evenly weighted sum of two systems' individual resilience, RS₅ produces the largest total resilience. The proposed method can help decision makers search optimum joint restoration strategy, which can significantly enhance both systems' resilience. - Highlights: • We propose a method to assess resilience of interdependent infrastructure systems. • We consider unidirectional interdependencies from power system to gas system. • Multi-systems' restoration processes are solved by using genetic algorithm. • Effectiveness of five restoration strategies are compared and analyzed. • Interdependency-based strategies produce the largest total resilience