Natural Structural Systems and Forms

Abstract

Organic and natural solutions have great value as they have, over time, been shaped by nature. Incorporating these organic and natural solutions in building design offers the challenge to quantify these solutions and to derive systems that are adaptable, constructible and cost effective. Adaptations and mathematical derivations that use nature’s mechanics in structural design have led to innovations in structural systems. These organically-inspired structural systems typically exhibit interesting aesthetic qualities which are not necessarily intuitive. Two design examples are explored which incorporate nature’s mechanics. First, geometric properties of bamboo, as they relate to structural shape, material placement and efficiency, are examined and applied to the China World Trade Center (CWTC) Tower Competition. Second, the logarithmic spiral—found in forms ranging from all the way from shells, seeds, and plants to spider webs, hurricanes, and galaxies—was interpreted and applied to the ultra-tall Transbay Transit Tower Competition, scientifically mimicking natural force flows of a cantilevered structure to its foundation. Influenced by developments in other fields of practice using evolutionary computational methods, novel efforts by designers have begun to yield custom and innovative methodologies for the determination and application of organic and natural solutions to practical structural design problems. First, genetic algorithms were applied to the design of the 365 meter tall Al Sharq Tower to be located in Dubai, United Arab Emirates. This unique and slender tower (aspect ratio of 10:1) employs a perimeter spiraling filigree of high-strength steel cables to resist gravity and lateral loads resulting in a column free exterior. Genetic optimization is employed to facilitate a broader search of cable profile solutions. Perimeter cable size, spacing and pitch are varied to identify an optimal cable arrangement. Second, a structural system integrated with the building envelope is generated using gradientbased algorithms and is employed for the proposed Gemdale Tower Competition submission to be located in Shenzhen, China. The location and trajectory of the perimeter members are determined by optimization techniques, which move and manipulate material in a free-form manner to determine the optimal solution for the complex form.