"TWIST" BRIDGE | VLAARINGEN
VLAARDINGSE VAART BRIDGE – Let’s do the Twist
The cyclist and pedestrian bridge crosses an over 50 m wide canal named Vlaardingervaart in the province of South Holland. This bridge is actually a box girder bridge which was almost entirely re-built by West 8 Urban Design & Landscape Architecture. Since the ends of the bridge were twisted 90°, the original box structure has scarcely been discernible anymore. It is this special design feature that gave the bridge its nickname: the Twist.
The four surfaces of the box girder now feature double truss girders. This not only makes the surfaces stiff but also allows relatively slender girders to be used. The truss girders in the twisted walls support the bridge and provide lateral stability. The twisting of the bridge ends is not only a gimmick but also ensures lower vibrations.
The bridge consists of a total of 400 girders. The edges and end portals are rotationally rigid and are fitted with the heaviest girders. The wall thickness of the other girders was determined on the basis of the forces they are subjected to. This means that their cross-sections were kept the same although the material was used efficiently – which is also interesting from the construction cost perspective.
During the construction period a make-shift workshop was set up. This allowed the boxes to be welded under controlled conditions, to then be galvanised and finally painted in brilliant red on site. With the help of two 500 ton cranes the bridge was finally lifted to the right position.
ABT was in charge of the engineering design & consulting, site supervision and project monitoring.