San Marcos Bridge

From HighestBridges.com
Revision as of 19:35, 23 November 2009 by Sakowski (talk | contribs)
Jump to navigationJump to search

San Marcos Bridge
Puente San Marcos
Xicotepec de Juárez, Puebla, Mexico
715 feet high / 218 meters high
561 foot span / 171 meter span
2012

SanMarcosView.jpg


Mexico has become fond of the beam bridge style known as the “fin back”. First used on the towering Papagayo bridge in 1993 on the México City-Acapulco highway, it was used again in 2005 on the similar sized Texcapa bridge on the still unfinished México City-Tuxpan highway. The San Marcos river bridge is also located on the same highway and won’t be finished until at least 2012. Upon its completion, this extremely high bridge will not only be the biggest fin back bridge ever built but its central pier of more than 715 feet (218 mtrs) will be the second highest in the world after the Millau Viaduct in France. Unlike the two previous Mexican fin backs which only have one span, San Marcos will have two main spans, each 561 feet (171 mtrs) in length.

A prestressed beam bridge with a highly variable depth of prestressing, the fin back design is unique for having the internal cables at their highest as they pass over the piers, enclosed in a wall or “fin” of concrete. The triple hump profile may look similar to a cable stayed or extradosed bridge but the engineering has more in common with a beam bridge. Many consider the lower profile to be more attractive than a conventional prestressed beam bridge.

The first fin back bridge was built in Nuremberg, Germany for a commuter railway in 1969. In the U.S., the only one is the 1987 built Barton Creek bridge near Austin, Texas with a main span of 340 feet (103.5 mtrs).


San Marcos Bridge Elevation


SanMarcosAerial.jpg