Innovation: Lightweight Tensile Cable Structure
Location: Munich, Germany
By: Gunther Behnisch (architect) and Frei Otto (Structural Engineer)
The construction of the Munich Stadium started with the idea of building a structure that imitated the Alps and, most importantly, set a counterpart to the heavy, authoritarian stadium in Berlin so Germany could be shown in a new light. As a result, Gunther Behnisch and Frei Otto, often considered the world’s leading authority on lightweight tensile and membrane structures, collaborated and came up with the cloud like, wavy, tensile structure of the Munich Stadium.
The structure of the Munich Stadium consists of a continuous tensile surface that bridges not only the stadium but also all of the main buildings of the Olympic Games creating a series of volumes across the site. The canopy membrane is suspended from multiple vertical masts that allow for the dramatic curves across the surface to flow across the site changing form, scale, and sectional characteristics. As complicated as the structure looks to the visitor, Otto’s high precision in the design allowed for a simple assembly to one of the world’s most innovative and complex structural systems that have worked solely on the premise of tension.
Innovation:Prebabricated Housing on a Large Scale
Location: Montreal, Quebec
By: Moshe Safdie
Habitat 67, a series of prefabricated concrete units meant for large scale housing, was first introduced by Moshe Safdie on 1967 for the Expo 67 in Montreal, Canada. The final complex consists of 364 three dimensional prefabricated concrete cubes arranged in various combinations, reaching up to 12 stories in height to form 146 residences.
The project began as an experiment to achieve better and more affordable housing for people living in increasingly crowded cities around the world. Safdie felt that it was more efficient to make buildings in factories and deliver them prefabricated to the site. As a result, Safdie attempted to make a revolution in the way homes were built by factory mass production. The units were built in a factory beside the Habitat 67 site and then arranged in such a way that each man’s roof was another man’s garden. The arrangement of the units provided privacy and a sense of uniqueness.
Even though his project was successful in making it possible for a dense population to live in an urban environment with the pleasures of a private home and garden, the project failed to revolutionize housing in such ways and ultimately Habitat 67 became so famous that the apartment became much more expensive than Safdie originally envisioned.
Innovation: Space Frame/ Geodesic Dome
Location: Montreal, Quebec
By: Buckminster Fuller
The Montreal Biosphere, designed for the Expo 67, is the result of Buckminster Fuller’s work dealing with with the tensile relationships between members to create a stable structure that was aesthetically pleasing. His work on domes began in the 1950s after becoming interested in tensile relationships and in spheres, which had the largest volume to surface area ratio. Fuller’s dome projects have been used for the military, environmental camps, and exhibition attractions around the world. His work inspired many to be creative in dealing with complex geometry, tensegrity, and lightweight structures.
Though Fuller was not the first to create a geodesic dome (rather, it was Dr. W. Bauersfield in the 1920s), he did receive the United States patent after popularizing his idea with the Montreal Biosphere in the Expo 67. The Montreal Biosphere’s covering of the dome burned in 1976, but the structure still stands at 250 feet in diameter and 200 feet high. Currently it is known as Biosphère and houses an interpretive museum, remaining a symbol of the Expo and of thin-shell structure .
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Innovation: Tensile Cable Roof (dynamic relaxation)
Location: West German Pavillion Roof, Montreal, Quebec
By: Frei Otto
Developed using a form-finding structural engineering principle called dynamic relaxation, the aim of which is “to find a geometry where all forces are in equilibrium”
The West German Pavilion Roof, designed for the Expo 67 at Montreal, is one of the many lightweight and tensile membrane structures for which Frei Otto is known. Although it took him several years to develop this system, it took only six weeks for the German Pavilion to be built in 1967.
His system used a network of steel cables suspended from eight slender steel masts of varied height, situated at irregularly intervals and supported by steel cables anchored outside the structure. The roof was then covered by a translucent plastic skin. The roof produced a new beautiful interior space lit through the transparent plastic odd-shaped windows in the roof. The tent and all of its components were fabricated in Germany.
Although the building wasn’t cheap to build since it was a new concept, Frai Otto’s innovation had potential not only because its steel and plastic roof weighted only 150 tons, about one third to one fifth of normal roofing materials, but also because it had the ability to adapt to the irregular topography of any site. `