Optimal Configuration of Structural Systems for Tall Buildings

Structural systems for tall buildings have evolved to produce higher lateral stiffness more efficiently, and the efficiency of a structural system is significantly influenced by its geometric configuration. Therefore, once a particular structural system is selected for a tall building, it should be configured very carefully to maximize its structural efficiency and, at the same time, satisfy other non-structural design requirements integratively. This paper investigates optimal configurations of today's prevalent structural systems for tall buildings. Among various structural systems developed for tall buildings, the systems with diagonals are generally more efficient because they carry lateral loads by their primary structural members' axial actions. When the primary lateral load resisting system is located over the building perimeter, the system's efficiency can be maximized. Tall building structural systems with perimeter diagonals include braced tubes and more recently developed diagrids. Braced tubes of various column spacing and diagonal configurations are comparatively studied. Diagrid structures of various uniform and varying angle diagonals are studied to determine more efficient configurations. Another structural system widely used for today's tall buildings is outriggers structures. Optimal stiffness distribution between the building core and perimeter mega-columns, connected to the core through outrigger trusses, is investigated for outrigger structures.