The National Stadium (Stadion Narodowy) was the venue that hosted the opening cerimony along with group matches and knockout stage games at of the European Football Championship EURO 2012 hosted in Poland and Ukraine.
The National Stadium is constructed at the location of the old “Stadium of the decade”. Designed by the group JSK (GMP and SBP), the stadium has a seating capacity of 55,000 across two tiers on 10 levels. The permanent roof covers the entire seating area whereas the inner roof above the field is designed to be retractable.
The roof design principal is based on the spokes of a bicycle wheel: n 72 steel columns support a compression ring where the radial cable girders 71 m long converge supporting the membrane structure. In all the column axis the cable structure is composed of an upper radial cable, a lower radial cable and a series of hangers in between connected from the compression ring and the upper pick up points to the 4 upper tension ring cables 70 mm diameter and to the 6 lower tension ring cables 125 mm diameter. Each ring is made of 420 m of locked coil cables joint in three points with couplers CYC.
The inner roof consists of 60 radial orientated cables 55 mm and 60 mm that span from the spire in the center of the structure to the upper tension ring composing the primary structure of the retractable roof. The central needle is stabilized and supported by 12 suspension cables 145 mm diameter with a length equal to 72 m that are running from the four corners point of the lower tension ring.
The project was carried out 11 months from the contract award.
|Wire||n. 2090 cables of Zn95Al5 FLC and OSS in 23 different diameters, ranging from 17 mm to 150 mm. A total length of approximately of 40 km and a weight of 1.800 tonnes. The FLC strands are connected to the forks and cylindrical sockets with polyester resin, while the OSS cables are fixed to the sockets by swaging.|