A Hybrid Office Tower- ULS and SLS Dynamic Wind Study A Study of Parameters Affecting Different Wind Response Modes and Dynamic Performance of Tall Buildings

Abstract

This thesis investigates the dynamic response of tall timber–concrete hybrid office build ings subjected to wind-induced vibrations, with a focus on occupant comfort according to ISO 10137:2008. It evaluates how different structural configurations influence the along-wind, across-wind, torsional, and combined responses of a high-rise building. A parametric study was carried out, varying core thickness, bracing system, aspect ratio, and added mass. Finite element models were developed and linked to a parametric workflow usingGrasshop per and Python. The results show that the along-wind response governs all configura tions, while the relative importance of across-wind and torsional responses varies with the structural strategy. However, considering only the along-wind response is not suf ficient for investigated configurations, and all three response modes should be assessed together. Serviceability in terms of occupant comfort governed both structural configuration and height. While the ultimate limit state was analysed, it was not governing for all studied configurations. Wind-induced accelerations were most effectively reduced by increas ing stiffness through diagonal bracing or a thicker core. Changes in aspect ratio signifi cantly reduced accelerations without additional material, indicating that early floor plan optimisation can be effective. However, with increasing height, timber–concrete hy brid structures become less material-efficient, requiring large concrete cores and added mass to meet serviceability criteria. The most efficient configurations were those up to 20 storeys. Overall, the thesis highlights the importance of considering all three response modes early in the design of tall timber–concrete hybrid buildings, as structural configuration strongly influences wind-induced vibration performance.