Tropical Cyclone Wind Fragility Assessment for Industrial Specialty Structures: The Case of Field-Erected Cooling Towers

This study presents a parameterized fragility model for understudied industrial specialty structures subjected to tropical cyclone extreme winds using the case of field-erected cooling towers. First, a probabilistic wind demand model is adopted to determine tropical cyclone wind pressures for the envelope components as well as the structural system (main wind force resisting system). The capacities of envelope components are characterized by probability density functions. The structural capacity is modeled using parametric OpenSees models. Monte Carlo simulations for the limit state evaluations are leveraged to train surrogate models that predict conditional damage state probabilities for multiple functionality-based targets. Fragility models parameterized on significant predictors across the hazard intensity and structural portfolio parameter space afford ready application to risk assessment in coastal industrial regions. The derived fragility models are leveraged to obtain the class-average fragility curves and assess the fragilities of the Houston Ship Channel industrial portfolio. Overall, this work addresses gaps in the literature by posing a state-of-the-art method for hurricane wind fragility analysis that parametrically addresses heterogeneous portfolios of specialty structures to allow efficient but tailored damage estimation of industrial structures under tropical cyclone winds.