Editing Cable-stayed bridge (section)

==Variations==

===Side-spar cable-stayed bridge===
[[File:Puente atirantado.PNG|thumb|right|[[Puente de la Unidad]], joining [[San Pedro Garza García]] and [[Monterrey]], a Cantilever spar cable-stayed bridge]]
A [[side-spar cable-stayed bridge]] uses a central tower supported only on one side. This design allows the construction of a curved bridge.

===Cantilever spar cable-stayed bridge===
Far more radical in its structure, the [[Puente del Alamillo]] (1992) uses a single [[Cantilever spar cable-stayed bridge|cantilever spar]] on one side of the span, with cables on one side only to support the bridge deck. Unlike other cable-stayed types, this bridge exerts considerable overturning force upon its foundation and the spar must resist the bending caused by the cables, as the cable forces are not balanced by opposing cables. The spar of this particular bridge forms the [[gnomon]] of a large garden [[sundial]]. Related bridges by the architect [[Santiago Calatrava]] include the [[Puente de la Mujer]] (2001), [[Sundial Bridge]] (2004), [[Chords Bridge]] (2008), and [[Assut de l'Or Bridge]] (2008).

===Multiple-span cable-stayed bridge===
[[File:Живописный мост 2012.jpg|thumb|[[Zhivopisny Bridge]] in [[Moscow]] is a multiple-span design.]]

Cable-stayed bridges with more than three spans involve significantly more challenging designs than do 2-span or 3-span structures.

In a 2-span or 3-span cable-stayed bridge, the loads from the main spans are normally anchored back near the end [[abutment]]s by stays in the end spans. For more spans, this is not the case and the bridge structure is less stiff overall. This can create difficulties in both the design of the deck and the pylons.
Examples of multiple-span structures in which this is the case include [[Ting Kau Bridge]], where additional 'cross-bracing' stays are used to stabilise the pylons; [[Millau Viaduct]] and [[Mezcala Bridge]], where twin-legged towers are used; and [[General Rafael Urdaneta Bridge]], where very stiff multi-legged frame towers were adopted. A similar situation with a suspension bridge is found at both the [[Great Seto Bridge]] and [[San Francisco–Oakland Bay Bridge]] where additional anchorage piers are required after every set of three suspension spans – this solution can also be adapted for cable-stayed bridges.<ref>{{cite journal
 |doi= 10.2749/101686601780324250
 |last= Virlogeux
 |first= Michel
 |title= Bridges with multiple cable-stayed spans
 |journal= Structural Engineering International
 |date= 1 February 2001
 |volume= 11
 |issue= 1
 |pages= 61–82
 |s2cid= 109604691
 }}</ref>

===Extradosed bridge===
[[File:Twinkle_Kisogawa_bridge02.jpg|thumb|right|The Twinkle-Kisogawa is an extradosed design, with long gaps between the cable supported sections.]]

An [[extradosed bridge]] is a cable-stayed bridge with a more substantial bridge deck that, being stiffer and stronger, allows the cables to be omitted close to the tower and for the towers to be lower in proportion to the span. The first extradosed bridges were the [[Ganter Bridge]] and [[Sunniberg Bridge]] in Switzerland. The first extradosed bridge in the United States, the [[Pearl Harbor Memorial Bridge (Connecticut)|Pearl Harbor Memorial Bridge]] was built to carry I-95 across the Quinnipiac River in New Haven, Connecticut, opening in June 2012.

===Cable-stayed cradle-system bridge===

A cradle system carries the strands within the stays from the bridge deck to bridge deck, as a continuous element, eliminating anchorages in the pylons. Each epoxy-coated steel strand is carried inside the cradle in a one-inch (2.54&nbsp;cm) steel tube. Each strand acts independently, allowing for removal, inspection, and replacement of individual strands. The first two such bridges are the [[Penobscot Narrows Bridge]], completed in 2006, and the [[Veterans' Glass City Skyway]], completed in 2007.<ref>{{cite press release
 |publisher= American Society of Civil Engineers
 |url= http://news.thomasnet.com/companystory/515472
 |title= Bridging To The Future Of Engineering
 |date= 12 March 2007
 |access-date= 8 March 2008
 |archive-date= 10 October 2008
 |archive-url= https://web.archive.org/web/20081010044956/http://news.thomasnet.com/companystory/515472
 |url-status= dead
 }}</ref>