The bridge spans 56 meters, about 70 meter above the valley, and quite a peculiar feature: it connects places with a height difference of 22 meter. It's not only a bridge, but a staircase.
Photo from lixelle
Photo from Marco Zanoli
It's a cable stayed bridge. The wood plattform (the bridge deck) hangs from steel cables which, as you already know, deform accordingly. Its funicular (the shape the cable adopts when it deforms), together with the steep stair, give rise to a powerful structure.
|General forces: the weight of the bridge is supported by the upper cables in tension.|
The bridge deck is inclined, and it pushes on its lower support (that's ok, business as usual), but it pulls from the upper support. That's a different story: the bridge's own weight is trying to drag the foundation into the river. How can you avoid that?
|The forces you have to stand if you don't want everything to fall down cliff!|
Moreover: the cables pull inward (that is, deep into the gorge as well!) thus, something has to be done to prevent the fall: an outward force is more than required. The foundation is responsible for that and, apart from its design (have a look at it here), it must be really heavy. Its own weight is its only tool. Actually (have a look below, at the details section), the foundation of this apparently light bridge weighs seven times more than the bridge itself. It's not what you see, but also what you don't see.
- More information about the bridge, and pictures of the building process.
- Traversiner Tobel, Graubünden, Switzerland
- Concept: Conzett Bronzini Gartmann AG
- Year: 2005 (built from May to August 2005)
- 56 m (footbridge)
- 95 m (main cable)
- steel cables and profiles
- concrete foundation
- 26 ton (bridge)
- 192 ton (concrete foundation)