Vibration Control in High-Rise Buildings for Multi-Hazard

Abstract

Increasing population and migration of people to cities has led to the construction of high-rise buildings. High-rise buildings have received a renewed interest in many city business locations, where land is scarce, as per their economic, sustainability and other benefits. Taller and taller towers are being built everywhere in the world. However, the increased frequency of multi-hazard disasters makes it challenging to balance between a resilient and sustainable construction. As a saying, ‘with new inventions come new problems’. High-rise buildings usually have issues with increased wind loads brought by, for instance, hurricanes, which can decrease their serviceability and cause failure of the structure. Although floor accelerations under wind loads are lower than those under earthquake loads, they occur for a relatively long time that raises comfort and serviceability issues. However, inter-story drifts under wind loads can raise security issues. The results presented in this thesis show that high-rise and slender buildings designed for wind may be safe under moderate earthquake loads, regarding the main force resisting system. Nevertheless, nonstructural components may present a significant percentage of loss exposure of buildings to earthquakes due to higher floor accelerations. Accordingly, the effect of earthquakes on tall buildings cannot be ignored. Damping devices are used to mitigate wind effects in tall buildings. These damping devices can also reduce the earthquake effects, but not to the full extent. In this thesis, the performance of a tuned mass damper (TMD) is studied under wind and earthquake loads (multi-hazard loading). A 76-story benchmark building is used in the analysis under multi-hazard loading. A new type of TMD called pounding tuned mass damper (PTMD) has growing importance in the reduction of earthquake effects. We adapt this PTMD for tall buildings and study its performance under multi-hazard loads, and compare it with a conventional TMD. In addition, the performance of viscous dampers in reducing earthquake effects is investigated. The main objective of the current study was to further the understanding of the impact of multi-hazard loading, brought by wind and earthquakes, on the behavior of high-rise buildings, in order to apply such knowledge to design.