![]() ![]() Bridges with perforated spandrels can be found worldwide, such as in China ( Zhaozhou Bridge, 7th century). The Zhaozhou Bridge, with a length of 167 feet (51 m) and span of 123 feet (37 m), is the world's first wholly stone open-spandrel segmental arch bridge, allowing a greater passage for flood waters. In China, the oldest existing arch bridge is the Zhaozhou Bridge of 605 AD, which combined a very low span-to-rise ratio of 5.2:1, with the use of spandrel arches (buttressed with iron brackets). ![]() Richmond Bridge, oldest operational bridge in Australia (1825) Such low rising structures required massive abutments, which at the Venetian Rialto bridge and the Fleischbrücke 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. The three elegant arches of the Renaissance Ponte Santa Trinita (1569) constitute the oldest elliptic arch bridge worldwide. The Ponte Vecchio, Florence, Italy (1345)Ĭonstructions such as the acclaimed Florentine segmental arch bridge Ponte Vecchio (1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The bridge at Trezzo sull'Adda, destroyed in the 15th century, even featured a span length of 72 m (236 ft), not matched until 1796. Span lengths of 40 m (130 ft), 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 ( Devil's bridge and Pont Grand) and with arch types as different as semi-circular, pointed and segmental arches. The 14th century in particular saw bridge building reaching new heights. Gothic pointed arches were also introduced, reducing lateral thrust, and spans increased as with the eccentric Puente del Diablo (1282). In medieval Europe, bridge builders improved on the Roman structures by using narrower piers, thinner arch barrels and higher span-to-rise ratios on bridges. The late Roman Karamagara Bridge in Cappadocia may represent the earliest surviving bridge featuring a pointed arch. 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 790 m-long (2,590 ft) long Puente Romano at Mérida. Trajan's bridge over the Danube featured open- spandrel segmental arches made of wood (standing on 40 m-high (130 ft) concrete piers). The 330 m-long (1,080 ft) Limyra Bridge in southwestern Turkey features 26 segmental arches with an average span-to-rise ratio of 5.3:1, giving the bridge an unusually flat profile unsurpassed for more than a millennium. The Romans also introduced segmental arch bridges into bridge construction. ![]() The outside was usually covered with brick or ashlar, as in the Alcántara bridge. Roman engineers were the first and until the industrial revolution the only ones to construct bridges with concrete, which they called Opus caementicium. in the Pons Fabricius in Rome (62 BC), one of the world's oldest major bridges still standing. Their bridges featured from an early time onwards flood openings in the piers, e.g. The Romans built both single spans and lengthy multiple arch aqueducts, such as the Pont du Gard and Segovia Aqueduct. Generally, Roman bridges featured wedge-shaped primary arch stones ( voussoirs) of the same in size and shape. The advantages of the 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. 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. 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). A list of Roman bridges compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges, a substantial part still standing and even used to carry vehicles. Īlthough true arches were already known by the Etruscans and ancient Greeks, the Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. ![]() The stone corbel arch bridge is still used by the local populace. Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. See also: List of Roman bridges, List of medieval stone bridges in Germany, and List of medieval bridges in France The Roman Alcántara Bridge, Spain (built 103-106 AD) The Anji Bridge, 6–7th century AD ![]()
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