Zollhaus Bridge, Switzerland

On a mountain road close to Fribourg, Switzerland, the Zollhaus Bridge, a reinforced concrete bridge built in 1917, had to be replaced. The adopted conceptual design was based on a reinforced concrete deck because reinforced concrete is the best material to carry the highly concentrated wheel loads and the torsion and bending induced by the skew geometry. The construction cost of the bridge was comparable to the cost of a conventional concrete bridge. It is interesting to note that the design procedure, mainly dictated by economical aspects, led to a pleasing appearance of the bridge in the alpine environment.