Standards Development

Scope

This document presents an alternative, simplified performance-based wind design (PBWD) method for tall concrete buildings with typical shapes. It aims to standardize a procedurally simplified process of PBWD, which uses a direct evaluation method without reliability assessments to make practical applications easier. It covers various levels of performance objectives including inelastic wind design, methods for inelastic wind design, determination of aerodynamic wind loads, numerical modeling and performance evaluation of concrete buildings.

The simplified process for inelastic wind design is suitable for designs of concrete tall buildings with typical shapes and wind load conditions. This document provides simplified process with limited conditions. Detailed performance assessment using wind tunnel tests may be required for the design of buildings with unusual conditions.

The applicability of the simplified procedures is subject to limitations related to both wind action determination and structural response. With respect to wind actions, the wind load formulation in accordance with ISO 4354 may be used for tall concrete buildings with typical shapes, regular mass and stiffness distributions, limited plan or vertical eccentricity, and without significant topographical, interference, or aeroelastic effects. Buildings that fall outside these conditions, including those with pronounced aerodynamic sensitivity or substantial aeroelastic response, shall be evaluated using wind tunnel testing to obtain reliable wind loads. With respect to structural behavior, the proposed framework permits only limited inelastic deformation under extreme wind actions. Where larger inelastic demands are allowed or where wind load reduction factors exceed recommended values, additional verification shall be performed to confirm safety against low cycle fatigue and damage accumulation, using advanced numerical modeling or experimental validation.

It should be noted that this document is not intended to supersede national standards or regulations that mandate an elastic design approach. Rather, it aims to provide a standardized, alternative procedure for engineers in jurisdictions where a performance-based design philosophy is permitted or deemed appropriate.