Timber-concrete composite bridge in a historical context, Siegburg

The district town of Siegburg is relieving pressure on Kaiserstraße by creating a new transport link between Burggasse and Ringstraße, thereby diverting the through traffic currently crossing the road for pedestrians, cyclists and cars. This measure is being implemented in the form of a footbridge connecting the two streets across a moat. The area beneath the footbridge will be developed as a green space offering an attractive environment in which to linger, whilst at the same time making the adjacent city wall and moat more accessible to visitors. The resulting route between Burggasse and Ringstraße, with its direct link to Kaiserstraße, is intended to invite people to walk through, linger and experience this historic area.

The footbridge structure will be carefully integrated into the urban environment and the surrounding green space. The abutment on the Burggasse side will be positioned so that it lies behind the historic city wall, which currently runs underground, meaning that the footbridge will span the city wall. The footbridge is planned with two intermediate piers and features a curved, S-shaped layout. Due to a difference in height of approximately 1.5 metres between the connection at Burggasse and Ringstraße, a gentle ramp is planned leading from Ringstraße to the start of the bridge.

The planning team’s aim was to take sustainability aspects into account right from the planning stage, which significantly influenced the choice of structural system for the footbridge. The use of a composite timber-concrete superstructure means that sustainable building materials are employed where they can best demonstrate their advantages: the composite construction allows the use of reinforced concrete in this structure to be significantly reduced, whilst the use of European natural stone for the caps on the sides of the footbridge ensures that a highly durable and sustainable material is utilised.