- Alconétar Bridge
The Alconétar bridge on the river
Tagus inSpain is one of the oldest stone segmentalarch bridge s in the world, predating other examples such as theZhaozhou Bridge in China andPonte Vecchio in Europe (both of which are still in use today). However thePonte San Lorenzo is another smaller Roman segmental arch bridge that predates this one by more than 200 years. The bridge is Roman and its construction is attributed by some toTrajan 's architectApollodorus of Damascus [O’Connor, Colin: "Roman Bridges", Cambridge University Press 1993, ISBN 0-521-39326-4, P. 109 ] , who also built the timber-archedTrajan's Bridge in the early 2nd century.The bridge was relocated from its original position when the
Alcántara reservoir was created in the province of Cáceres,Extremadura , Spain [Troyano, Leonardo Fernández, "Bridge Engineering - A Global Perspective", Thomas Telford Publishing, 2003] . Two original segmental arches were preserved, of 6.7m and 7.2m span, and a span-to-rise ratio of between 4 and 5, as were segmental arches from a later date [ [http://www.csarmento.uminho.pt/docs/ncr/historical_constructions/page%20247-256%20_45_.pdf "A brief analysis of the Roman bridges of the way La Via de la Plata", Limón, Hortelano & Fernández] ] . There is evidence from the position of piers that segmental spans up to 10m may have been present in the original construction.References
See also
*
Roman bridge
*List of Roman bridges External links
* [http://www.spanisharts.com/arquitectura/i_roma_ingenieria.html Dimensioned elevations showing the surviving arches]
* [http://users.servicios.retecal.es/jomicoe/Alconetar.jpgPhotograph showing three of four surviving arches]
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