Editorial: Special Issue on "Codification of wind loading of structures"

This editorial summarizes the scope of a Special Issue aimed to examine the current stateof-the-art and practice associated with the wind engineering load and design standards. Contributions address the major wind design standards around the world. Specifically, the contributions deal with recent developments in the field of codification with emphasis on new technologies, experimental methods and advances in computer simulations that could serve as an additional resource for the designer. Several wind engineering design standards have been recently updated or are currently under major revision because of the recent developments in the wind engineering field. Some examples are: EuroCode 1 – Part 1-4, ASCE 7-22, Australian/New Zealand Standards AS/NZS1170.2, Japanese Building Codes (AIJ, BCJ, etc.) and the Chinese National Standard for Wind Loads. For instance, in ASCE-7 22 a new chapter describes, for the first time, the design against tornado wind hazards. In the revised Australian/New Zealand Standard AS/NZS 1170.2:2021 a profile and topographic multipliers are included for a special region, dominated by downburst winds from thunderstorms. The latest versions of codes and standards for windsensitive structures also include wind loads for special structures such as bridges, lattice towers, offshore platforms and wind-turbines support towers. This Special Issue contributes to the aims of the Journal of Wind and Structures and focuses on invited papers that either contribute to the advancement of the state-of-the-practice in wind load codification or provide a review of one or more standards. Papers selected for the Special Issue are examples of leading research and best practices in the field of wind load analysis and design. The selected studies include analysis of novel design formulas, extreme value analysis of wind speed and direction by collection of new data sets, experimental and computational methods specifically aiming at wind load codification. The selected contributions are selected from experts in each sub-field and discuss either a specific topic or a specific standard. Each selected paper was carefully and thoroughly reviewed by anonymous Reviewers, who are also experts in each field, prior to publication. Adhikari and Letchford (2023) studied wind speed data from Nepal and adjoining countries and examined extreme wind speed climatology for the region. Wind speed information for Nepal was adopted from the Indian National Standard and applied to two orographically different regions: above and below 3000 m elevation respectively. Comparisons of the results were based on relevant codes and standards. Bruno et al. (2023) investigated several design codes and standards, covering the use of Computational Wind Engineering and Computational Fluid Dynamics for wind-sensitive structures and built environment. Special attention was devoted to the findings of the Special Interest Group on Computational Wind Engineering of the Italian Association for Wind Engineering (ANIV-CWE). The same group is currently advising UNI CT021/SC1 in supporting the drafting of new Annex K of the revised Eurocode 1 – Part 1-4 on wind actions. Finally, the study discusses avenues open to future development at technical and practical levels. Holmes et al. (2023) investigated the latest revision of AS/NZS 1170.2 that incorporates new research and knowledge on strong winds, climate change, and shape factors for new structures of interest such as solar panels. Australia and New Zealand cover climatic zones from tropical to cold temperate, and virtually every type of extreme wind event: gales from synoptic-scale depressions, convectively-driven downdrafts from thunderstorms, tropical cyclones, downslope winds, and tornadoes. A 'climate change multiplier' was included and several modifications for the structural analysis of solar panels, curved roofs, poles and masts, high-rise buildings and other dynamically wind-sensitive structures. Kopp (2023) discusses the substantive changes to the ASCE 49-21 Standard "Wind Tunnel Testing for Buildings and Other Structures". The most significant changes are the requirements for wind field simulations that utilize (i) partial turbulence simulations, (ii) partial model simulations for the flow around building appurtenances and requirements for determining wind loads on items at multiple sites and in various configurations. Modifications were implemented to allow constructing models for small elements placed on large buildings at the scales typically available in boundary layer wind tunnels. The study also examines research needs with respect to aerodynamic mechanisms, the role of turbulence on separatedreattaching flows on building surfaces, etc. Lee et al. (2023) analyzed the Korean Design Standard (KDS) that will be updated with two major revisions on the assessment of wind load and performance-based wind design (PBWD). Major changes on the wind load assessment are the wind load factor and basic wind speeds. Additional modifications include pressure coefficients, torsional moment coefficients, spectra, and aeroelastic instability. PBWD is a newly added section in the KDS. Ricciardelli (2023) examined the new EN 1991-1-4 Eurocode 1 – Part 1-4 on wind actions. The papr summarizes the work of the project team from August 2017 to April 2020. The document includes several modifications and new sections: updated design wind maps, improved wind models, updated force and pressure coefficients, review of procedures for evaluating dynamic response. Personal recommendations by the Author are also discussed. Wang et al. (2003) compared the "Code of Practice on Wind Effects in Hong Kong" of 2019 with the latest revision of the Architectural Institute of Japan (AIJ) Recommendations for Loads on Buildings, and the Australian/New Zealand Standard, AS/NZS 1170.2:2021. Comparisons include design wind speeds, profiles and wind speed multipliers. The study also highlighted differences in the basic design wind speed and exposure factor estimation, together with future development trends.