Lecture 16 : Structural Systems of Skyscrapers – 1

This lecture introduces the structural systems used in modern skyscrapers and explains how tall buildings safely resist gravity, wind, and earthquake forces. It highlights why lateral loads are the controlling factor in skyscraper design and explains the importance of structural systems as the backbone of tall buildings. The lecture covers key ideas such as material efficiency, speed of construction, fire safety, and architectural flexibility, along with construction methods like slip-form concrete cores. It introduces early systems such as the steel moment-resisting frame, explaining its use in buildings like the Seagram Building by Mies van der Rohe, and discusses why this system became less efficient for very tall buildings. The session then explains the shift toward tube structural systems, pioneered by Fazlur Rahman Khan, setting the foundation for understanding more advanced skyscraper structures in later lectures.