Multiobjective Optimization for Hurricane Retrofit to Improve Coastal Community Structural and Socioeconomic Resilience

Abstract

With recent hurricanes causing devastating economic losses, structural damages, and societal impacts on coastal communities, residential building hurricane mitigation measures have gained increasing attention. However, retrofits are often costly and therefore beget inherent tradeoffs. In particular, the balancing of the postdisaster losses against upfront mitigation costs remains a constant challenge for community resilience planning. Existing mitigation optimization frameworks on the community scale have primarily focused on seismic hazards and typically have weak integration of the structural damages with the socioeconomic impacts. In the present study, finite element modeling of the residential buildings is applied to better incorporate the structural damages under combined wind and wave loadings. A multiobjective linear constrained optimization framework for improved residential building hurricane retrofit is developed to balance the structural damages, home displacements, morbidities, net direct economic losses, and initial mitigation expenditures under hurricane threats. For the present analysis, the mitigation actions of building elevation and improved construction practices are simulated. The framework is tested in a case study for an existing coastal community under 50-, 100- and 500-year hurricane events considering community-specific socioeconomic factors. The generalized pattern search algorithm is selected to determine the Pareto-optimal solutions. The results indicate large potential reductions in social, structural, and economic losses under optimized mitigation, but tradeoffs exist if the mitigation technique is found to be cost-ineffective, such as in the case of the improved construction practices. The findings highlight the importance of informed decision-making and home retrofits in improving community resilience.