Challenges:One of the most interesting triumphs in technological foresight was an early 1990 proposal for a 150-story skyscraper in downtown Los Angeles. The project, which was published in an article entitled "Mega-structure: A New Concept for Supertall Buildings," came to define a new set of rules in tall building construction. Collaborating with partner-in-charge, David Martin, of A.C. Martin & Associates, the project became an opportunity to strategize on enhancing many conventional structural design issues, including seismic and wind engineering, load path, construction scheduling, cost and serviceability.
Solution:Due to new understanding and concepts in seismic and wind engineering, the
Mega-structure Project opened the door to ideas about lightness, slender structural forms and reduced natural damping in skyscrapers. At 150 stories, the wind forces alone are enough to dictate the performance of the building, despite its location in an earthquake zone. The diamond-shaped floor plan (two triangles) improves the building's aerodynamics and allows integrative strategies, such as cross-sectional carrying elements and slots (formed by separating the two triangles), to disrupt the organization of vortices. The vertical carrying elements, in a structure this large, were also designed to serve as function spaces (e.g., elevators, stairs, ventiliation) because of their sheer girth. The actual structural system is seen as similar in concept to the lace-braced columns of the Eiffel Tower.