Development of Shell Structures | Structural Systems
In this article, we will discuss “Surface Active Structure System” with examples for better understanding….
In my earlier articles, we discussed “Structural Systems in the Post Modernist Period” and “Development of Suspended Structures“. Reading about different types of Structural Systems and their basis and purpose of evolution will help you understand the varied concepts of Structural Systems.
In this type of structure system, a thin curved structure is so shaped to transmit applied forced by compressive, tensile and shear stresses that act in the plane of the surface. They are usually constructed of concrete reinforced with steel mesh.
Shell construction began in the 1920s; the shell emerged as a major long-span concrete structure in postmodernism. Thin parabolic shell vaults and even complex forms i.e. hyperbolic paraboloids stiffened with ribs have been built with spans up to about 300 feet (90m). Thickness of the shell with this system can be achieved even less than 0.5 inches (1.25cm) thick. One of the most famous example of this is Sydney Opera House.
The shape of this majestic structure has been achieve with the help of plastic behaviour of the material. In this, the shells were constructed out of 2400 precast ribs and 4000 roof panels in an on-site factory. By this solution, they were able to avoid the need for expensive formwork construction.