A heuristic method to identify optimum seismic retrofit strategies for critical infrastructure systems

Abstract

Retrofitting critical components of a critical infrastructure system to improve its seismic performance has been considered as the most frequently used mitigation strategy in both literature and practice. This article mainly studies this mitigation strategy and formulates the seismic retrofit optimization problem for critical infrastructure systems under a limited retrofit budget in a general form, and then proposes a heuristic method to solve the problem efficiently in terms of the optimality gap and the computational cost. The proposed method mainly includes three steps: (1) generates a limited number of component damage scenarios to reformulate the problem as an approximated model; (2) adopts a component importance-based method to reduce the solution space and applies the integer L-shaped method to solve the approximated model; (3) employs the sample average approximation method to enhance the solution quality. To demonstrate the performance of the proposed method, it is applied to identify the optimal retrofit strategies for the Shelby power transmission system, the IEEE 14-bus test system, and the IEEE 118-bus test system and also compared with several existing methods. Results show that the proposed method is significantly more efficient than those existing methods. For the IEEE 14-bus test system, the proposed method gets almost exact solutions, with errors less than 0.29%; for the other two systems, it returns the best solutions among all methods under various retrofit budgets.

A multi‐perspective framework for seismic retrofit optimization of urban infrastructure systems

“…67,68 The method based on the performance improvement can also be called as retrofit efficacy-based method, whose accuracy is very close to the exact solution method for small-scale systems and with much lower computational cost, as verified in authors' previous research. 41 This article further improves the accuracy of the retrofit efficacy-based method by integrating it with the enumeration method, with the main steps as follows.…”

“…Readers interested in the full mathematical model are referred to the authors' previous research. 41 Step two: adopt the retrofit efficacy-based method to compute the importance value (i.e., the performance improvement) of each component using a limited number of component damage scenarios, that is, 𝐼 𝑘 𝑐 for component 𝑐 of infrastructure 𝑘, then reformulates the original retrofit optimization problem to be the following knapsack problem:…”

“…In fact, urban infrastructure systems are not isolated but interdependent with each other, which may aggravate the damage consequences. [39][40][41] Researchers also have studied the retrofit optimization problems of interdependent infrastructure systems against various hazards. Dueñas-Osorio et al 42 proposed a simplified method to identify critical components for retrofitting interdependent power and water networks located in an earthquake-prone region; Kong et al 43 proposed a model to search the best component hardening strategy through maximizing the resilience of interdependent electric, gas, and oil transmission networks against regional natural hazards.…”

“…Most of the above studies mainly consider single systems. In fact, urban infrastructure systems are not isolated but interdependent with each other, which may aggravate the damage consequences 39–41 . Researchers also have studied the retrofit optimization problems of interdependent infrastructure systems against various hazards.…”

Multi-agent Modeling of Hazard-Household-Infrastructure Nexus for Equitable Resilience Assessment

“…Some utilities would prioritize the restoration of the service areas with greater populations; however, this restoration strategy might favor residents living in a larger metropolitan area and might adversely affect people in rural areas (Liu et al 2007). Other strategies mainly focus on physical characteristics, such as prioritizing the components with a high (Liu et al 2021;Ouyang and Dueñas-Osorio 2014). The model uses priorities assigned to the components in the network to generate the different repair strategies.…”