Computationally Cost-effective Seismic Rehabilitation Optimization framework for Road Networks

Abstract: Seismic events can significantly disrupt the functionality of road networks by damaging critical infrastructure assets such as pavements and bridges. Proactive rehabilitation can mitigate these impacts, but resource limitations make it impossible to rehabilitate all assets simultaneously. Given the critical need for resilient road networks, transportation agencies aim to mitigate the adverse effects of seismic events, focusing on enhancing resilience within resource constraints. However, many existing optimization models rely heavily on traffic simulations and extensive Monte Carlo simulations, which are computationally demanding and time-consuming. The objective of this research is to develop cost-effective topology-based optimization algorithms that provide an efficient alternative to computationally demanding concrete infrastructure system vulnerability simulations. The research was conducted in three stages: (1) characterizing performance uncertainties of road network assets; (2) estimating network functionality before and after earthquake using traffic simulations and formulating a stochastic combinatorial optimization problem to determine the optimal rehabilitation strategy using a genetic algorithm (GA); and (3) evaluating and selecting eight topological connectivity metrics for seismic rehabilitation optimization of the road network, with each optimized using a genetic algorithm. A city-level road network in California was selected for this analysis, utilizing probabilistic seismic fragility functions to assess critical assets and their failure probabilities. When applied to the benchmark road network, the proposed approach identified all eight topological metrics have significantly reduced optimization runtime. The results demonstrated that these topological surrogates provide a substantial reduction in computational cost with minimal loss in solution quality, offering a cost-effective framework for road network seismic rehabilitation. This approach aids in efficient resource allocation, enhancing the resilience of road networks in seismically active regions.