04:00 PM - 05:30 PM
19 October 2023

NEW! Tornado Loads in ASCE 7-22 and 2024 IBC

State of the Industry / Profession

Until recently, ASCE 7 and model building codes specifically excluded tornado hazards in the design of conventional buildings. Therefore, it is not surprising that our buildings and infrastructure perform poorly in tornadoes – given that they are not designed to resist tornadic loads. As a result, tornadoes kill more people in the U.S. than hurricanes and earthquakes combined, with most tornado fatalities occurring inside buildings. Additionally, tornadoes and tornadic storms cause more insured losses than hurricanes and tropical storms combined.

The panelists will provide a brief overview of tornado hazards, the rationale for consideration of tornadoes in conventional engineering design, the latest science on tornadic winds/wind-building or other structure interaction, and an overview of the new tornado load requirements in the ASCE 7-22 standard and the forthcoming 2024 International Building Code. Key changes to the ASCE 7-22 wind load provisions, which are incorporated into the tornado loads, will also be addressed.

The new tornado requirements represent nothing less than a paradigm shift in wind load design – one that will reduce damage from tornadoes as well as other windstorms across much of the central and southeast U.S. Tornado loads on several example buildings at locations across the country will be shown in comparison to wind loads, e.g., uplift loads on roofs can double or more. Impacts of the increased tornado loads on structural and on roof system selection and design will be discussed, along with highlights of an economic analysis examining the estimated cost impacts of the tornado load provisions.

PDH 1.5