National Stadium Bucharest

National Stadium "Lia Manoliu", built in 1953, has been replaced by a multifunctional stadium with a retractable roof. Due to economical and technical aspects the spoke and wheel roof structure was chosen. The compression ring along the outside is supported by hinged steel columns. The radial cables of the outer roof span between the compression ring and the lower tension ring cable bundle. Onto this cable bundle a planar polycarbonate roof is attached. The overhang of this roof element ensures the drainage of the convertible inner membrane roof. The inner roof runs along the lower radial cable of the inner, spider-like cable structure. This inner cable structure is clamped to the outer compression ring using compression bars and tension cables. The convertible membrane roof can be stored in a membrane garage in the centre of the roof structure.