Search

This paper presents a procedure for response prediction in high-rise buildings under wind loads. The procedure is illustrated in an application example of a tall building exposed to both cross-wind and along-wind loads. The responses of the building in the lateral directions combined with torsion are estimated simultaneously. Results show good agreement with recent design standards; however, the proposed procedure has the advantages of accounting for complex mode shapes, non-uniform mass distribution, and interference effects from the surrounding. In addition, the technique allows for the contribution of higher modes. For accurate estimation of the acceleration response, it is important to consider not only the first two lateral vibrational modes, but also higher modes. Ignoring the contribution of higher modes may lead to underestimation of the acceleration response; on the other hand, it could result in overestimation of the displacement response. Furthermore, the procedure presented in this study can help decision makers, involved in a tall building design/retrofit to choose among innovative solutions like aerodynamic mitigation, structural member size adjustment, damping enhancement, and/or materials change, with an objective to improve the resiliency and the serviceability under extreme wind actions.

• Estimated response is more influenced by horizontal than by vertical tap density. • The tap density influence is the strongest on the base torsion. • A good estimation of global responses does not guarantee quality of local responses. This study examines the influence of pressure tap density and layout on estimated wind effects of a 47-story steel building for which the Database-Assisted Design procedure is used to calculate the base shears, base overturning moments, member Demand-to-Capacity Indexes (DCIs), inter-story drift ratios, and floor accelerations. From an original tap layout (20 rows by 5 columns, total 100 taps per façade), a total 16 tap layout cases were created varying vertical and horizontal tap densities. The influence of the tap density on the estimated wind effects of interest was then investigated. In most cases the calculated structural response is significantly more influenced by the horizontal than by the vertical tap density. The influence of the tap density was found to be strongest on the estimated base torsion, followed by the member DCIs, the base shears, and the base overturning moments. The acceptable pressure tap density depends on the structural response of interest. The results show that the current practice of considering global quantities like the overturning moment and/or the base shear as indicators of the adequacy of tap resolution for structural design can be misleading. [ABSTRACT FROM AUTHOR]