Fazlur Khan’s Legacy: Towers of the Future
Director of Structural and Seismic Engineering at Skidmore, Owings & Merrill LLP, USA
Dr. Khan’s contributions to the design of tall buildings have had a profound impact on the profession of architecture and engineering. His clear approaches to structural systems have led to efficient and often expressive structures. He had a unique understanding of forces, materials, behavior, as well as art, literature, and architecture. It would be difficult to find any world-wide practices in the design of tall buildings that have not been directly or indirectly influenced by his work.
Kahn’s approach to design was based on the fundamentals for engineering principles with a clear understanding of load path. Long before there was widespread focus on environmental issues, Kahn’s designs promoted structural efficiency and least use of materials resulting in the least carbon emission impact on the environment. Kahn’s partnership with architectural / engineering greats such as Bruce Graham and Myron Goldsmith led to elegant, integrated solutions. Most of his designs were conceived considering pre-fabrication and repetition of components so projects could be quickly built with minimal errors. Kahn was keenly interested in performance of structural systems over an expected life. Recognizing a building’s life cycle and issues of abnormal loading demands, he developed concepts carefully integrated into severe wind environments as well as early concepts of seismic isolation of structures.
Kahn’s seminal work of developing tall building structural systems in structural steel and reinforced concrete based on building height are still used today as starting point when considering design options for tall buildings. These system ideas have led to other concepts with many of the building heights far taller than those considered by Kahn. His ideas have inspired others to expand the possibilities in tall building design many of which have a specific consideration of life-cycle engineering and the effects of the structures on the environment. These structures are designed to behave naturally during earthquakes where traditional concepts of material ductility are replaced by mechanisms that allow for movement during ground shaking while protecting material elasticity. Parametric modeling has allowed for new considerations of life-cycle behavior by careful consideration of applied load, boundary conditions, and material placement. Towers of the future will consider a more holistic approach to design incorporating and integrating building services and enclosure systems directly into design.
This lecture and paper will consider the influence on Kahn’s work on developing ideas for towers of the future through specific building examples and theories important to creating new concepts for life-cycle engineering.