Waagner Biro Bridge Systems offers the complete range of special bridges (pedestrian bridges, cable stayed bridges, suspension bridges, pipeline bridges, truss bridges and arch bridges).
Pedestrian bridges are used to overcome obstacles such as roads with heavy traffic, rivers or railway lines. Waagner-Biro has built numerous pedestrian bridges either as truss girder, arch, cable stay or other types. Claddings and walkways are carried out in steel, timber or glass. Architectual lighting of the pedestrian bridge creates another added value.
Elegance of shape combined with load-bearing function are the main design parameters of arch bridges. Depending on the conditions of the site, the carriageway can be suspended from hangers or arranged on supporting columns above the arch. Arch bridges already played a major role in the early years of Waagner-Biro. Depending on the characteristics of the site, bridges are built with their arch above the carriageway (“suspended“ carriageway), or with their carriageway over and supported by the arch (“elevated“ carriageway). Arch bridges are cost effective in spans from 100m to 300m, arch bridges constructions for smaller spams are used in particular cases too.
Cable Stayed Bridges
Cable-stayed bridges consist of one or several pylons, from which slanting stay cables support the main deck. The span of cable-stayed bridges ranges on average between 100m and 500m. Two major types of cable arrangements have proven to be effective: In the fan-shaped design the cables are connected to the top of the tower, in which case every stay cable is anchored in the main span, runs over the tower saddle and is anchored in the span section behind. Alternatively, in the harp-shaped design, the cables running from the deck to the tower are practically parallel to each other, as a result of which they are spread out evenly along the height of the tower.
Suspension bridges are used for the largest spans. The cost-effective range of use is for spans between 300m and 1,500m. In specific cases the construction of smaller suspension bridges of less than 300m would be appropriate. One can also build smaller bridges with spans of approx. 100m.
The construction consists of two support towers, to which main support cables are fastened on both sides. On the suspension cables, high strength hangers are mounted, which hold the carriageway and the main girder beneath them. Tractive forces occur on the cables, which must not only take up the entire load of the traffic and of the supporting structure itself, but also the dynamic wind and earthquake loads, which are especially relevant for suspension bridges. The pressure loads that occur are diverted into the bottom chord via the towers.
Supporting structures in the form of suspension bridges are commonly used to bridge the gap over large rivers or valleys for oil or gas lines, conveyor belts, water pipes or drainage channels. Back in the 1960s, Waagner-Biro developed a unique carrying system of Y-shaped pylons with three cables inclined spatially towards each other for better stabilisation of the pipeline bridges. The system is characterised by two oblique bearing walls arranged in a V shape, supplemented by a central pre-tensioning cable running along the tube route and curving upwards.
Bridges with main girders produced as truss constructions have the advantage of relatively low weight, as regards both the construction and the individual parts (truss beams). Bridges of this kind are built for open spans of up to 300m and can be used for roads, railways and other combined applications. Truss bridges can be supplied in bolted or fully welded design. Waagner-Biro has over a 165 years of experience with the construction of truss bridges (truss girders on both sides above the carriageway) and suspended truss girders (carriageway on the upper chord as well as truss girders below the carriageway).