Exogenous windborne debris: Definition and required extent of surrounding buildings for modeling in hurricanes

Abstract

Modeling and estimating the damage to the built environment caused by hurricane winds is an essential requirement to enhance community resilience. Consideration of damage to a building’s envelope caused by windborne debris impact is necessary. To model this damage for a certain subdivision of houses, debris generated in neighboring subdivisions, defined as exogenous debris, must be taken into account. Existing physics-based damage estimation models do not consider the effect exogenous windborne debris has on the estimated damage due to hurricane winds. This paper provides a methodology to identify the extent of the neighboring subdivisions that needs to be considered during damage simulation to accurately account for exogenous windborne debris. The presented methodology is based on first identifying the extent of the neighboring subdivisions through a simulation-based strategy which follows an iterative scheme. For each size increment, the iterative scheme estimates the number of exogenous windborne debris using a physics-based damage estimation model. The single building solution is then generalized to a subdivision of any arbitrary shape. The proposed methodology is applied to analyze a hypothetical residential community in Miami, FL. Analysis results show the effect on the required extent of the neighboring subdivisions of the hurricane maximum wind speed, the floor-area ratio and the resistance of the building envelope components. The analysis concludes with a regression model that can be used to estimate the size of the neighboring subdivisions to be used in damage estimation models.