Stadium Freiburg, Germany

The roof structure is a lightweight cable truss with a superimposed steel frame that supports the roof covering and the loads from technical equipment such as lighting, sound system, video walls, and the photovoltaic system. This roof structure allows for flexible design of the stadium adapts to the local conditions, allowing for greater flexibility in site selection within the permitted building area. Since the roof height is significantly lower than that of a cantilevered roof, this offers the crucial advantage of preventing the roof structure from encroaching on the unobstructed view of the airfield. The structure consists of open or fully enclosed spiral cables with a tensile strength of 1570 N/mm² or 1770 N/mm². The structural system comprises a ring cable/tension ring that is connected via radial cables to a compression ring, forming a composite cross-section. The ring cable and radial cables are prestressed to their own weight, thus establishing the planned geometry. The compression ring is placed on the surrounding row of supports. Inside, the roof cantilevers over the tension ring. The translucent roof covering, made of multi-chamber polycarbonate sheets, is laid on this cantilevered steel structure. The roof structure is erected after the load-bearing reinforced concrete structure has been completed. Thanks to the lightweight roof structure, the stadium's columns and foundations can be designed much more economically, as the loads transferred from the roof reduce the ground pressure. The roof is stiffened by symmetrically arranged bracing.

Architect
gmp International GmbH

Activity of LAP
Total contractor competition (implementation competition) as structural engineer for the construction company Züblin
2nd Place in competition
Structural engineering according to HOAI, up to service phase LPH3 with quantity and cost determination