Pedestrian Bridge in Stuttgart
To avoid the additional bending moments that occur with asymmetric loading and that usually result in bulky structural members in conventional forms of construction, a horizontal post-tensioned steel cable was fixed on the underside of this bridge. Under symmetrical loading, the cable is a zero-force member. Under asymmetric loading, it restrains the arch of the bridge – or draws it back into its initial position. This form of construction necessitated a system of hinged joints and the use of wire mesh to the balustrades. The bridge girder consists of a pair of curved steel flat beams linked by cross-members and diagonals to form a horizontally rigid diaphragm. The cable below is fixed at both ends in concrete abutments.