EXHIBITION

Main Pavilion by Shigeru Ban Architects
The temporary nature of the Main Pavilion lead to the decision to create a Paper Tube Structure that also strived to minimize foundation requirements. The design had gone through many challenges and alterations to arrive at the final design.
The original allocated site of the Pavilion was on a triangular site which drove the form of the first design. The plan is a 30m equilateral triangle broken up into a finer grid of 3m triangles. The perimeter of the Pavilion composed of large columns at a 3m pitch create a colonnade that defines the interior space of the open-air structure. These columns support the entire roof structure which is a series of trusses composed of smaller diameter paper tubes. Atop the truss is a light translucent corrugated polycarbonate roof. The structural innovation for this design is at the column-to-roof-truss connection where wooden joints are inserted into the paper tubes to create a moment resisting joint; a first-time challenge for a paper tube structure.
The second design kept the same plan form of a 30m triangle but the paper tube structure was a three dimensional dome structure that would come down to meet the ground at the three corners. Because there is a minimum number of supports to carry the whole load of the roof, it is necessary for the foundations to become very large and heavy (concrete) and has to support large beams that span between the foundations. The hexagonal steel plate joints of the roof grid has to be made of inconsistent angles and the paper tube segments would be of differing lengths. The predetermined geometry of the geodesic roof makes this structure a sleek low lying form.
When it was then determined that the location of the Pavilion would be elsewhere within the larger Biennale site, there was no longer a restriction to make a triangular structure. The third design proposed a square plan using shipping containers as foundations. Shipping containers are very much a common sight in Hong Kong, and are appropriate for creating temporary foundations, firstly, because they can be leased and returned after use, and secondly because they themselves are rigid structures with a broad surface coverage for bearing and they can be filled with sand bags to achieve the necessary resistance against uplift forces. Three containers per side are spaced at approximately 6m intervals for an even arrangement of walls and openings. A continuous steel beam is secured to the top of the containers using standard container connection joints to make up the perimeter support for the paper tube roof. The paper tube roof is composed of four equilateral triangular faces that lean against each other to make a pyramidal form. Each equilateral triangle, similar to the first design, is composed of a smaller grid of triangles using all similar steel plate connections.
The form of this design creates a prominent presence within the landscape and also as seen from the skyline from across the bay. The plan encloses a large regular shaped interior accessible from all sides with a high ceiling. The openings can be closed off in numerous arrangements to flexibly accommodate the various events that will be held. Additionally, there was a second option to this design that reduced the number of containers to two per side, resulting in a smaller interior space and a lower overall height.
The final design was a take-off from the previous design but incorporated a trussed paper tube roof in the form of a vault. The vault roof has a broad span of 30m, a depth of 30m, and is supported by two rows of evenly spaced out shipping containers. The roof covers the same regular 30m by 30m plan as in the previous design, but is open on either end of the vault. Within the Biennale site, the structure is oriented so that the open ends of the roof frames the view towards Hong Kong Island.
Throughout the design process, discussions and inputs from the building authorities had made the design process quite difficult. Because this was the first paper tube structure to be built in Hong Kong, there was a reluctance to approve the building as other typical temporary structures in other cities. Therefore the built structure was compromised to meet the demands resulting in an over engineered structure and finally the depth of the
structure had to be shortened to compensate for the extra costs incurred. The realization of this project was made possible by the tireless efforts of a collaborative team of architects, engineers, curators, consultants, and builders.

2009 Hong Kong & Shenzhen Bi-city Biennale of Urbanism \ Architecture: Bring Your Own Biennale asks you to help envision a new model metropolis that uses social capital as the main driving force.
 
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