Introduction

The workshop's purpose was to assess the current state of the art of tornado design in practice and to support the development of a Tornado Research Roadmap to advance knowledge in this area and further its application in practice.

The workshop scope covered the broad subject area of tornado research and design methodologies and the following associated sub-topics:

This workshop's development began with the selection of the Workshop Steering Committee (WSC), which consisted of leading experts in the field of tornado engineering who have been involved in developing the current design provisions within ASCE/SEI 7-22. WSC members were Alex Griffin, P.E., S.E, M.ASCE, of Burns & McDonnell; Cherylyn Henry, P.E., F.SEI, F.ASCE, of the ZAPATA Group, Inc.; Marc Levitan, Ph.D., F.SEI, M.ASCE, Lead Research Engineer for the National Windstorm Impact Reduction Program (NWIRP) of the National Institute of Standards and Technology (NIST); Frank Lombardo, Ph.D., EIT, A.M.ASCE, of the University of Illinois; John van de Lindt, Ph.D., F.SEI, F.ASCE, Professor at Colorado State University; and Peter Vickery, Ph.D., P.E., F.SEI, F.ASCE, NAE, of Peter J. Vickery Consulting. Each WSC member also invited a young professional to participate in the workshop and report development process: Shane Crawford, Ph.D., A.M.ASCE, of the University of Alabama; John Haney, A.M.ASCE, of Burns & McDonnell; Blythe Johnston, S.M.ASCE, of Colorado State University; Lauren Mudd, Ph.D., P.E., M.ASCE, Senior Engineer at Applied Research Associates; Korah Parackal, Ph.D., CPEng, A.M.ASCE, of the Insurance Institute for Business & Home Safety; and Zach Wienhoff, EIT, of Haag Engineering (see Figure 1-1).

The WSC started meeting in November 2023 to begin developing the workshop's content and select leaders in the field to invite to the workshop. The WSC decided on the following topics as the most critical issues to address at present and selected the participants based upon their expertise in these areas:

To understand the current state of the art of tornado design, the WSC developed a reading list of relevant documents to share with workshop participants. These reading list documents were used to formulate the workshop sessions (see Appendix B.3). As a result of developing the reading list, the WSC determined that Chapter 32 of ASCE/SEI 7-22 is the only current design document available to the profession and thus represents the state of the art.

The two-day workshop was convened on March 7–8, 2024, to identify the highest-priority research needs that form this report's basis. The WSC, wind engineering practitioners, building design professionals, federal agency partners, not-for-profit organizations, academics, and researchers for buildings and other structures attended the workshop, which was also open to members of the public. The workshop was held at ASCE headquarters in Reston, Virginia (see Figure 1-2).

The format of the SEI Tornado Design Workshop enabled all 66 participants to contribute in multiple ways. The workshop began with several state of the practice presentations and included time for participants to ask questions. The participants were then divided into breakout groups based upon the six workshop topics selected by the WSC. In these breakout groups the participants were given four tasks:

Each breakout group then reported back to the full group of workshop participants in a general session and described its prioritized research and development needs. Following these presentations and subsequent discussions, the workshop participants prioritized the separate breakout group research and development needs (Figure 1-3). Section 5 summarizes the top identified research needs, and Appendix A further discusses some of these research needs.

The framework adopted for the workshop to advance tornado hazard research and improve community resilience consisted of in-depth consideration of six areas essential to the overall research, design processes, and understanding of needs to improve community resilience. These areas include the research areas of Tornado Climatology and Near-Surface Wind Characteristics, Tornado/Structure Interaction, Design of Residential Structures, Design using ASCE/SEI 7-22, Design of Tornado Shelters and Safe Rooms, and Tornado Effects on Non-building Structures Beyond ASCE/SEI 7-22. The following briefly describes these areas of interest.

Following Section 1, Introduction, the workshop report is organized as follows:

The report includes four appendixes. Appendix A further discusses the highest priority research needs identified during the workshop. Appendix B includes the workshop agenda, presentations, breakout session participants, and reading lists. Appendix C maps the priority research needs, as identified by the workshop participants, to the National Windstorm Impact Reduction Program (NWIRP). Appendix D lists the workshop participants alphabetically.