The 200 m timber tower - A study on the possibilities of constructing a 200 meter tall timber building

Abstract

ABSTRACT As the interest in timber buildings is increasing, more attention is pointed towards highrise timber buildings. Partly because it is one of the main areas pushing the development within the field of timber structures. As the current tallest timber building, Mjöstornet in Brumunddal is approximately 10 times shorter than the world’s tallest building, Burj Khalifa, the intuition says that there is room for major improvements regarding tall timber structures. The aim of this thesis is therefore to investigate the possibilities to build a 200 m tall timber tower while still fulfilling the requirements for strength, stability and dynamics. In order to anchor the project in reality, the assumed building location is Gothenburg with the ground conditions of solid rock. Early in the study it was concluded that in order to push the height limits, the building design had to be improved compared to the existing timber buildings. The main geometries of interest turned out to be the circular shape thanks to its aerodynamical benefits. This base shape was applied in various ways, generating five different concepts ready for evaluation. Each of the five concepts were modelled and preliminary sized using Grasshopper and Karamba 3D, whereafter they were evaluated based on their dynamic performance, global stiffness, and a few other evaluation criteria. The evaluation was primary made with structural performance in mind and secondary with regard to comfort, quality and economical aspects. The results show that one of the concepts have great potential of reaching 200 m despite the uncertainties regarding joint stiffness and structural damping. Also, a few of the other concepts might be able to reach 200 m if subject to some structural and dynamical improvements. Key words: Acceleration