Modeling joint restoration strategies for interdependent infrastructure systems

<div><p>Life in the modern world depends on multiple critical services provided by infrastructure systems which are interdependent at multiple levels. To effectively respond to infrastructure failures, this paper proposes a model for developing optimal joint restoration strategy for interdependent infrastructure systems following a disruptive event. First, models for (i) describing structure of interdependent infrastructure system and (ii) their interaction process, are presented. Both models are considering the failure types, infrastructure operating rules and interdependencies among systems. Second, an optimization model for determining an optimal joint restoration strategy at infrastructure component level by minimizing the economic loss from the infrastructure failures, is proposed. The utility of the model is illustrated using a case study of electric-water systems. Results show that a small number of failed infrastructure components can trigger high level failures in interdependent systems; the optimal joint restoration strategy varies with failure occurrence time. The proposed models can help decision makers to understand the mechanisms of infrastructure interactions and search for optimal joint restoration strategy, which can significantly enhance safety of infrastructure systems.</p></div

Consequences of the interaction process.

<p>Consequences of the interaction process.</p

Time duration of the optimal strategy with change of <i>θ</i>/<i>φ</i>.

<p>Time duration of the optimal strategy with change of <i>θ</i>/<i>φ</i>.</p

The electric power network and the water supply network.

<p>The red squares nodes (P1-P10) are the power plant nodes, while the blue squares nodes (W1-W6) are the water plant nodes. The red lines are electric transmission lines, and the blue lines are water pipelines.</p

Parameters in joint restoration strategy model.

<p>Parameters in joint restoration strategy model.</p

An illustrative example of the interaction process.

<p>Substation node P6 physically fails at t = 1, and it is restored at t = 3.</p

The fitness value during different generations.

<p>(a) failures happening at 1 AM; (b) failures happening at 1 PM.</p

Numbers of functional nodes in two networks at each time step.

<p>(a) Initial node failures occur in the power network; (b) initial node failures occur in the water network.</p

Average hourly service consumption of Guilin in China.

<p>(a) electric power; (b) water.</p

Optimal restoration sequence for failures at 1 AM.

<p>Optimal restoration sequence for failures at 1 AM.</p