Editing Arch bridge (section)

== History ==
{{See also|List of Roman bridges|List of medieval stone bridges in Germany|List of medieval bridges in France}}
[[File:Bridge Alcantara.JPG|thumb|left|The Roman [[Alcántara Bridge]], Spain (built 103-106 AD)]]
[[File:Anji (Zhaozhou) Bridge 2011.jpg|thumb|The [[Anji Bridge]], 6–7th century AD]]
Possibly the oldest existing arch bridge is the [[Mycenaean Greece|Mycenaean]] [[Arkadiko Bridge]] in Greece from about 1300 BC. The stone [[corbel arch]] bridge is still used by the local populace.<ref>[http://odysseus.culture.gr/h/2/eh251.jsp?obj_id=1710 Hellenic Ministry of Culture: Mycenaean bridge at Kazarma] {{webarchive |url=https://web.archive.org/web/20080408153052/http://odysseus.culture.gr/h/2/eh251.jsp?obj_id=1710 |date=8 April 2008 }}</ref> The well-preserved [[Hellenistic]] [[Eleutherna Bridge]] has a triangular corbel arch.<ref>Nakassis, Athanassios (2000): "The Bridges of Ancient Eleutherna", ''The Annual of the British School at Athens'', Vol. 95, pp. 353–365</ref> The 4th century BC [[Rhodes Footbridge]] rests on an early [[voussoir]] arch.<ref>{{harvnb|Galliazzo|1995|p=36}}; {{harvnb|Boyd|1978|p=91}}</ref>

Although [[true arch]]es were already known by the [[Etruscans]] and [[ancient Greeks]], the [[Ancient Rome|Romans]] were &ndash; as with the [[Vault (architecture)|vault]] and the [[dome]] &ndash; the first to fully realize the potential of arches for bridge construction.<ref>Robertson, D.S.: Greek and Roman Architecture, 2nd edn., Cambridge 1943, p. 231: <blockquote>"The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch, the vault and the dome."</blockquote></ref> A list of [[Roman bridge]]s compiled by the engineer Colin O'Connor features 330 [[List of Roman bridges#Masonry bridges|Roman stone bridges]] for traffic, 34 [[List of Roman bridges#Timber and stone pillar bridges|Roman timber bridges]] and 54 [[List of Roman bridges#Aqueduct bridges|Roman aqueduct bridges]], a substantial part still standing and even used to carry vehicles.<ref>O'Connor, Colin: "Roman Bridges", Cambridge University Press 1993, p. 187ff. {{ISBN|0-521-39326-4}}</ref> A more complete survey by the Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 countries (including former [[Yugoslavia]]).<ref>Galliazzo, Vittorio (1994), I ponti romani. Catalogo generale, Vol. 2, Treviso: Edizioni Canova, {{ISBN|88-85066-66-6}}, cf. Indice</ref>

Roman arch bridges were usually [[semicircular]], although a number were segmental arch bridges (such as [[Alconétar Bridge]]), a bridge which has a curved arch that is less than a semicircle.<ref>{{cite web|url=http://imgs.ebuild.com/woc/M880252.pdf |title=Designing the segmental arch |last=Beall |first=Christine |year=1988 |publisher=ebuild.com |access-date=8 May 2010 }}</ref> The advantages of the [[circular segment|segmental]] arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent the bridge from being swept away during floods and the bridge itself could be more lightweight.<ref>Temple, Robert. The Genius of China: 3,000 Years of Science, Discovery, and Invention. New York: Touchstone, 1986.</ref> Generally, Roman bridges featured wedge-shaped primary arch stones ([[voussoir]]s) of the same in size and shape. The Romans built both single spans and lengthy multiple arch [[Roman aqueducts|aqueducts]], such as the [[Pont du Gard]] and [[Segovia Aqueduct]]. Their bridges featured from an early time onwards flood openings in the piers, e.g. in the [[Pons Fabricius]] in Rome (62 BC), one of the world's oldest major bridges still standing.

[[File:AcueductoSegovia edit1.jpg|thumb|left|[[Segovia Aqueduct]] ({{circa|100 AD}})]]

Roman engineers were the first and until the [[Industrial Revolution]] the only ones to construct bridges with [[Roman concrete|concrete]], which they called [[Opus caementicium]]. The outside was usually covered with brick or [[ashlar]], as in the [[Alcántara Bridge]].

The Romans also introduced segmental arch bridges into bridge construction. The {{Convert|330|m||-long|abbr=on|adj=mid}} [[Limyra Bridge]] in southwestern [[Turkey]] features 26 segmental arches with an average span-to-rise ratio of 5.3:1,<ref>O'Connor, Colin: "Roman Bridges", Cambridge University Press 1993, p. 126 {{ISBN|0-521-39326-4}}</ref> giving the bridge an unusually flat profile unsurpassed for more than a millennium. [[Trajan's bridge]] over the [[Danube]] featured open-[[spandrel]] segmental arches made of wood (standing on {{Convert|40|m||-high|abbr=on|adj=mid}} concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the {{Convert|790|m||-long|abbr=on|adj=mid}} long [[Puente Romano]] at [[Mérida, Spain|Mérida]]. The late Roman [[Karamagara Bridge]] in [[Cappadocia]] may represent the earliest surviving bridge featuring a pointed arch.<ref>{{harvnb|Galliazzo|1995|pp=92, 93 (fig. 39)}}</ref>

[[File:Pont du Diable - Céret.JPG|thumb|[[Pont du Diable (Céret)|Devil's bridge]], [[Céret]], France (1341)]]

In [[medieval]] Europe, bridge builders improved on the Roman structures by using narrower [[pier (architecture)|piers]], thinner arch barrels and higher span-to-rise ratios on bridges. [[Gothic architecture|Gothic]] pointed arches were also introduced, reducing lateral thrust, and spans increased as with the eccentric [[Puente del Diablo (Martorell)|Puente del Diablo]] (1282). With more advanced design and bridge-building techniques, the alternative informal name of [[Devil's Bridge]] became more widely used across Europe, because many people could not believe that these were man-made and capable of carrying the size of loads that they did.

The 14th century in particular saw bridge building reaching new heights. Span lengths of {{Convert|40|m||abbr=on}}, previously unheard of in the history of masonry arch construction, were now reached in places as diverse as Spain ([[Puente de San Martín]]), Italy ([[Castelvecchio Bridge]]) and France ([[Pont du Diable (Céret)|Devil's bridge]] and [[Pont Grand (Tournon-sur-Rhône)|Pont Grand]]) and with arch types as different as semi-circular, pointed and segmental arches. The [[Trezzo sull'Adda Bridge|bridge at Trezzo sull'Adda]], destroyed in the 15th century, even featured a span length of {{Convert|72|m||abbr=on}}, not matched until 1796.<ref>Troyano, Leonardo Fernández: Bridge Engineering. A Global Perspective, Thomas Telford Publishing, London 2003, {{ISBN|0-7277-3215-3}}, p. 49</ref>

[[File:Firenze.Ponte Vecchio01.jpg|left|thumb|The [[Ponte Vecchio]], [[Florence]], Italy (1345)]]

Constructions such as the acclaimed [[Florence|Florentine]] segmental arch bridge [[Ponte Vecchio]] (1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The three elegant arches of the [[Renaissance]] [[Ponte Santa Trinita]] (1569) constitute the oldest elliptic arch bridge worldwide. Such low rising structures required massive [[abutment]]s, which at the [[Venice|Venetian]] [[Rialto Bridge]] (1591) and the Pegnitz or [[Fleischbrücke]] (1598) in [[Nuremberg]] (span-to-rise ratio 6.4:1) were founded on thousands of wooden piles, partly rammed obliquely into the grounds to counteract more effectively the lateral thrust.

[[File:Ironbridge 6.jpg|thumb|[[The Iron Bridge]] at [[Coalbrookdale]], thereafter renamed [[Ironbridge]], over the [[River Severn]] Gorge in [[Shropshire]], [[England]] at the original centre of what became the [[Industrial Revolution]] — the first cast iron bridge, completed in 1781 with a single arch, designed by [[Thomas Telford]] and built using traditional woodworking techniques]]

In China, the oldest extant arch bridge is the [[Zhaozhou Bridge]] of 605 CE, which combined a very low span-to-rise ratio of 5.2:1, with the use of spandrel arches (buttressed with iron brackets). The Zhaozhou Bridge, with a length of {{conv|51|m|ft}} and span of {{conv|37.4|m|ft}}, is the world's first wholly stone open-spandrel segmental arch bridge, allowing a greater passage for flood waters.<ref name="Needham">Needham, Joseph. ''The Shorter Science and Civilisation in China''. Cambridge University Press, 1994. {{ISBN|0-521-29286-7}}. pp. 145–147.</ref> Bridges with perforated spandrels can be found worldwide, such as the [[Bridge of Arta]], (17th century) Greece and [[Cenarth Bridge]], (18th century) in Wales.

With the coming of the [[Industrial Revolution]], in the 18th and 19th centuries, stone and brick arches continued to be built by many prominent British [[civil engineer]]s, including [[Thomas Telford]], [[John Rennie (father)|John Rennie]], and latterly [[Isambard Kingdom Brunel]]. They also started the modern usage of different materials, such as [[cast iron]] — Telford designed the first bridge built of metal, completed in 1781, [[the Iron Bridge]] with a single arch of sections of cast iron constructed in traditional woodworking techniques — and then [[steel]] and [[concrete]], which have been increasingly used in the construction of arch bridges, to almost the exclusion of other materials. A key pioneer was [[Jean-Rodolphe Perronet]], who used much narrower piers, revised calculation methods, and exceptionally low span-to-rise ratios.