RAPID: Collection of Perishable Data on Wind- and Surge-Induced Residential Building Damage in Texas during 2017 Hurricane Harvey

Auburn University, Auburn AL

Investigators

Abstract

Windstorms and associated hazards, such as storm surge, routinely cause the most building damage of any natural hazard in the United States. To mitigate this damage, it is important to understand the relationship between wind speed and its characteristics and the resulting building damage. On 25 August 2017, Hurricane Harvey struck the coast of Texas as a Category 4 hurricane with a rare combination of high wind speeds and significant storm surge. Preliminary reconnaissance showed that residential building performance in coastal communities in Texas exposed to the brunt of Hurricane Harvey's impacts was highly variable, even for similar building types that should have experienced similar wind speeds and storm surge levels. This variability demonstrates gaps in the fundamental knowledge of the relationship between hurricane hazards and building damage. This Grant for Rapid Response Research (RAPID) will support field data collection on residential building performance during Hurricane Harvey in order to fill these gaps by formally evaluating the hurricane hazard-to-building damage relationship through direct observation. A better understanding of the hazard-to-damage relationship and the factors that influence it can be used to advance hurricane-resistant building design methodologies and society's resilience to windstorms. All data acquired during the field work will be shared with the engineering research community through the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) Data Depot available at https://www.designsafe-ci.org. The collected building performance data, matched with wind speed observations or estimates, will provide a library of engineering case studies for use in the classroom to educate the next generation of engineers and architects on the impacts of hurricanes on buildings. Current building design and damage prediction methods assume that windstorm damage is primarily a function of standardized wind speed magnitude, local terrain, and building characteristics, implicitly ignoring any potential differences between extreme wind event types for the same given wind speed, and any effects from potentially coexisting hazards such as storm surge. The goals of this RAPID project are to 1) collect a representative, spatially-referenced database of residential building performance during Hurricane Harvey, 2) develop hurricane fragility functions for wind based on the field data collected, and 3) establish a framework for evaluating the effects of enhanced hazard conditions, such as storm surge or mesovortices within the hurricane eyewall, in addition to high winds, and other extreme wind events such as tornadoes, on the wind-to-damage relationship. Residential building damage data will be collected, from major areas with significant building stock along the impacted Texas coastline, by a team of researchers and graduate students from Auburn University, University of Illinois at Urbana-Champaign, and University of Maryland. A guided cluster sampling approach over a large spatial area will be used to conduct detailed, ground-based surveys of single-family residential structures with geo-tagged photographs and field notes. The collected data will include the damage ratios for all major building components, characteristics of the building such as construction material and number of stories, and any evidence that could be used to estimate wind speed or storm surge height. The fragility functions developed from the empirical data will be used to facilitate the comparisons between wind-to-damage relationships, demonstrating differences in expected building performance during wind-only, wind and storm surge, and tornado events.