By: Hanan Rawashdeh
One of Toyo Ito’s admired designs is the Sendai-shi Mediatheque in Japan, a public building facilitating a variety of public activities. What stands out most in the project is the unconventional structural method used where the building seems to be lightly lifted by hollow columns that are formed by tubes of steel.
The three word components of the building are plate, tube and Skin. When investigating the project one finds that these three elements are expressed in their purest form. The “plate” referring to the thin slabs of the six level project, the “tube” being the columns that carry the load and the skin representing the outer layer of the façade constructed of double glazing for acoustic and buffer zone against solar gain.
The main reason behind this approach came from the nature of the building itself (a Public building). The emphasis to blur the boundary between architecture and urban space was achieved by having these tubes that form the untraditional lattice – like columns that work as light wells, enhance ventilation, occupy mechanical and even in some columns work as circulation. The application of these lettuce columns enables the sense of liberated discrepancies of the various programmatic elements. Freedom from all barriers makes the message of knowledge and culture the upfront and center of experience in the building. With the definable line removed between outside and inside, between programmed spaces and open spaces, between service users and service providers, between space and people to become an ambiguous and blurred connection.
Moving on to the structure of those lettuce columns it is important to note that without digital and computerized calculations the success of such a structure would be hard to achieve. The tubes are rounded in a circle of various diameters and different center point the higher they stretch. Each tube is fire resistant steel with a pipe section thickness of 139.8 – 241.8 mm in outside diameter) tube thickness varies from 9 – 39mm depending on loading requirements.
Sheaves that are ring like circulate these tubes in place and are welded to the sandwich thin floor planes. For better distribution of the load from the slabs to the columns, the floor plans contain three distinct web constructions in the plates. The area around the bundle of tubes, welded to the ring, joining them, is triangular based. The second area of the web connection is a square grid that covers the short distance between each column and the next. The third is a rectangular based grid. As a result the load distribution of the plates is transmitted from the rectangular to the square to the triangular/ radial web connection going down to the tubes.
In this case the design of the building is a simple approach with a twist in its structure making it stand out, proving that there doesn’t have to be many angles and masses to form great architecture. Sometimes using an unorthodox approach to structure can beautify the project in whole and make it unique.