Sunniberg Bridge, Switzerland

This five-bay cable-stayed bridge is supported by unusually low pylons on top of piers up to 60 m high. The slender deck consists of a continuous slab with slightly thickened edges. Together with the pylons and piers, it forms a structurally closed system. The parallel cables are fixed in steel sleeves in the recessed pylons, and the bridge was calculated in such a way that a single cable can be removed at a time for maintenance purposes without interrupting traffic. The curvature on plan allows changes in length to be absorbed by horizontal changes in the radius. The bridge is rigidly fixed at both ends without expansion joints. As a result, the piers are held almost immovably in position at the level of the carriageway.