Papaya stage – Zrće
The stage, that in the coming years, will attract looks and admiration of the public, and as presented by the architects and authors of the concept solution, it is a landmark of Croatian tourism, it required a lot of experience and knowledge in order to be made.
The stage gets its complex form from five arches with a span of 18.00m, each of which has three radii of curvature, torsion curvature and constant change of cross-sectional arches. This complex geometry of arches could not have been done through traditional approach as per form segment construction and position as per workshop drafts, but a new approach was applied. It was made in a specialized software application for development of steel structures so that digital data was extracted for CNC plasma in which the positions were cut. For assembly, that is, welding positions into sets, hole “markers” 3,0mm in diameter were used, on which segments were stacked without additional measuring. By the use of this
principle human error factor was avoided, and the only control of sets were radii given for each arch and four dimensions for each level of each set controlled the achieved geometry.
The steel structure of the Papaya club stage in Zrće was made from box welded profiles which formed the arches and extrusions were used for secondary construction. Utility grids that are used for hanging structures were derived from extrusions, whereas those were also made in curved forms, each of corresponding radius of curvature in order to follow the form of the main bearing structure. The plates used for welded box-sections were thick 8.0 mm, 10.0 mm and 15.0 mm, depending on the position in an arch, that is achieved through straining. The quality of materials for the whole construction was S235, except for the panel thickness 15.0 mm for which the quality of S355 was used.
The total weight of the steel structure above the foundation is 23,000kg, and the amount of reinforcement B 500B into the foundation was 6170 kg. The stability of the whole structure at the strongest wind in Croatia, that is, wind of 48.0 m/s, lies on the foundation into which approximately 50.0m³ of concrete C30/37 was used.