Editing Cable-stayed bridge (section)

==Comparison with suspension bridge==
[[File:Ada Bridge 2012.jpg|thumb|right|[[Ada Bridge]] at dusk in [[Belgrade]] ([[Serbia]])]]
[[File:Prins Clausbrug vanuit NO bekeken.JPG|thumb|right|Prins Clausbrug across the [[Amsterdam-Rhine Canal]] in [[Utrecht]] ]]

Cable-stayed bridges may appear to be similar to [[suspension bridge]]s, but they are quite different in principle and construction. In suspension bridges, large main cables (normally two) hang between the towers and are [[Earth anchor|anchored]] at each end to the ground. This can be difficult to implement when ground conditions are poor. The main cables, which are free to move on bearings in the towers, bear the load of the bridge deck. Before the deck is installed, the cables are under [[tension (mechanics)|tension]] from their own weight. Along the main cables smaller cables or rods connect to the bridge deck, which is lifted in sections. As this is done, the tension in the cables increases, as it does with the [[live load]] of traffic crossing the bridge. The tension on the main cables is transferred to the ground at the anchorages and by downwards [[compression member|compression]] on the towers.

<gallery class="center" caption="Difference between types of bridges" widths="180px" heights="120px">
File:Bridge-suspension.svg|Suspension bridge
File:Bridge-fan-cable-stayed.svg|Cable-stayed bridge, fan design
</gallery>

In cable-stayed bridges, the towers are the primary load-bearing structures that transmit the bridge loads to the ground. A [[cantilever]] approach is often used to support the bridge deck near the towers, but lengths further from them are supported by cables running directly to the towers. That has the disadvantage, unlike for the suspension bridge, that the cables pull to the sides as opposed to directly up, which requires the bridge deck to be stronger to resist the resulting horizontal [[compression (physics)|compression]] loads, but it has the advantage of not requiring firm anchorages to resist the horizontal pull of the main cables of the suspension bridge. By design, all static horizontal forces of the cable-stayed bridge are balanced so that the supporting towers do not tend to tilt or slide and so must only resist horizontal forces from the live loads.

The following are key advantages of the cable-stayed form:
* much greater stiffness than the suspension bridge, so that deformations of the deck under live loads are reduced
* can be constructed by cantilevering out from the tower – the cables act both as temporary and permanent supports to the bridge deck
* for a symmetrical bridge (in which the [[span (engineering)|spans]] on either side of the tower are the same), the horizontal forces balance and large [[earth anchor|ground anchorages]] are not required