2020 Tennessee-Arkansas Tornado Outbreak: Structural Assessments

Winds produced by tornadoes can impose extreme pressures capable of destroying or severely compromising the structural integrity of structures. Typical design wind loads can fall well below those produced by tornadoes, and as such, structural damage from tornado winds can be extensive. The intensity of the winds produces by a tornado can vary over a relatively short distance. Therefore, a significant disparity in the extent of damage affecting neighboring structures can also occur. This paper outlines key points to perform structural assessments to determine the extent of structural damage from tornadoes. It describes a systematic approach to the evaluation of structures considering the damage indicators and degrees of damage defined by the Enhanced Fujita Scale. This paper also describes basic factors to consider during the structural assessment to assist contractors and building consultants in preparing construction estimates to repair the structure, if repairability is an option. Several case studies involving tornado damage structural assessments will be discussed from tornadoes that occurred in Tennessee and Arkansas in the Spring of 2020.