ABSTRACT
Variations on current structural systems and the development of new systems are important for the next generations of ultra-tall buildings. For a building up to 40 stories, the proportion of core walls needed to surround the service areas naturally satisfies lateral and gravity requirements with wall thicknesses typically not exceeding 600 mm. Managing the placement of gravity loads on frames can further increase the frame's efficiency by using gravity to counteract uplift forces. Post-tensioned concrete frames within the perimeter of 500 West Monroe in Chicago were used to redistribute axial loads, provide additional clear spans between columns, and increase structural efficiency. The outer structural system follows the internode length with respect to mega-brace heights and mimics the culm wall fibers. The inner structural system also follows specified bamboo characteristics. Outriggers are taken as the 'diaphragm' in bamboo since outriggers tie perimeter structural systems in a similar manor to diaphragms in bamboo.
