UC Davis

Hurricanes are among the most destructive and costliest extreme weather events. The intensity of future hurricanes is generally expected to increase due to climate change effects. In this work, the potential effects of climate change on hurricanes and associated changes of the risks for residential buildings located on the coastal areas of the United States is investigated. A simulation method based on a comprehensive statistical analysis of historical data is developed to account for the changes in climatological conditions and their effects on the frequency and intensity of hurricanes. This method is applied to simulate the hurricane wind speed distributions under different climatological conditions in the US Atlantic Basin from Texas to Maine, which is one of the most vulnerable regions of the world to hurricane hazards. To this end, regression models for several different hurricane parameters are fit to the historical hurricane data. The proposed model is validated by comparing its predicted hurricane-induced wind speeds with available historical data and other existing models based on physics-based hurricane path simulation. This new model is found to reproduce very well historical wind speed distributions, and to provide wind speed projection results that are consistent with those of more computationally expensive models based on the simulation of hurricane tracks. The statistical characteristics of future potential hurricanes are simulated using the proposed model along with the climate projections presented in the 5th Assessment Report of the Intergovernmental Panel for Climate Change. The results of this study indicate that, by year 2060 and depending on the considered projection scenario, the design wind speeds along the US Gulf and Atlantic Coast corresponding to the different mean return intervals considered by ASCE 7 are expected to increase in average between 14% and 26%, which correspond to an average increase of the design wind-induced loads contained between 30% and 59%.To account for the effects of climate change on hurricane risk for structures, an appropriate methodology is presented, which extends the performance-based hurricane engineering (PBHE) framework to account for the nonstationarity of both hazard, induced by climate change effects, and vulnerability, produced by structural aging. The newly developed general nonstationary PBHE framework is implemented by performing a loss analysis on a benchmark low-rise single-family house over a 50-year design service life, for which climate change effects are accounted for by using the predictive model for the changes in the hurricane wind hazards, whereas structural aging is neglected. The effects of different modeling assumptions and solution approaches (including approximate estimates, time discretization, interpolation techniques, and models for annual discount rates), different locations, and different climate change scenarios on the means and standard deviations of the total losses are investigated. The performance comparison of different storm mitigation strategies is also performed as an application example. In general, the proposed methodology provides consistent results under different modeling assumptions; however, the modeling assumptions for the annual discount rates can affect the results significantly. Climate change effects are generally significant, with increases contained between 13.2% and 38.1% for the total loss means, and between 2.5% and 12.4% for the standard deviations of the total losses for the benchmark structure at the reference location of Pinellas Park, FL. The extended nonstationary PBHE framework is able to identify the optimal retrofit strategy in terms of costs and benefits for any given combination of structures, residential developments, locations, and climate scenarios. The proposed nonstationary PBHE framework represents an advancement in performance-based engineering, as it provides a rigorous approach to account for climate change effects and structural aging. The extended PBHE methodology is also used to investigate the combined effects of structural aging and increase in the hurricane hazard level on the hurricane risk for wooden single-family houses. To this end, a time series for the climatological condition variables during the lifetime of the structure is simulated and is used along with decay models for wood, adhesive, and nails to investigate the effects of aging and how different limit states of components are being modified. The changes in hurricane-induced losses due to the separate and combined effects of climate change and structural aging are investigated for a single-family residential building located in Miami, FL. It is found that the combined effects of climate change and aging can increase the total expected losses for the structure to more than 108% compared to the case where no climate change or aging is considered during the lifetime of the structure. The research presented in this dissertation represents an advancement not only in performance-based hurricane engineering, but generally in performance-based engineering, as it provides a rigorous framework that can be adapted to other single and multiple hazards to account for the effects (individually or simultaneously) of climate change and structural aging.