Cover Palasport of Busto Arsizio – Varese
General Data
- Fire Resistance: R60
- Coverd Area: 6800 m²
- Engineer Designer: Planchestainer
- Calculations: Micheletti Ingegneria
- Static Layout: geodesic, diameter 89 m
Busto Arsizio Palasport is an example of superb geodesic cover in laminated wood constructed by utilising special patented and hot galvanised steel nodes.
A geodesic dome in laminated wood is a hemispheric structure made of a network of beams resting on great circles (geodesics). Geodesics cross each other forming elementi triangular elements, which rest roughly on a sphere. The triangles are all very similar to each other and being stiff guarantee local solidity, while the geodesic shape formed by their sides distributes the stresses on the entire structure.
A geodesic dome is the only structure built by man that becomes proportionally more resistant as dimensions are increased.
When the structure forms a complete sphere, it is called geodesic sphere.
The cover for Busto Arsizio structure is constructed with the use of equally sized triangular elements, which act on the large circular drum representing the base. Among all structures built with straight elements, the geodesic dome is the one with the maximum ratio of weight to enclosed volume: structurally are much stronger than they appear by looking at the beams forming it. During construction of a new geodesic dome, there is a moment when the structure reaches the necessary “critical mass” and settles upward by lifting the scaffolding fixed to it.
Planning a geodesic dome is a very complex project, in part because there aren't any standard projects of geodesic dome of reference to be scaled according to needs, but every dome must be planned from scratch based on sizes, shape and materials. Some standards of planning exist based on adaptations of theoretical solids like icosahedron: basically they consist in projecting the face of the solid on the surrounding sphere surface. There isn't any perfect way to execute a similar operation because it is not possible to retain at the same time sides and original angles. The result is a solution of compromises based on triangles and geodesics only approximately regular.
The final result is impressive: it bears witness to the search of perfection through mathematical calculations and harmonious geometries.