The superstructure is a single continuous, segmentally constructed box girder, with two long center spans and two short end spans. The superstructure sits on the supports without transferring moment into the piers, which suggests that it was perfectly balanced during construction. That must be why it was built with two piers under the center of the bridge.
I wonder if this long bridge has prestressing tendons? I'm not sure what the longest reinforced concrete box girder bridge is, but this looks past the limit. The haunched girders undoubtedly helps.
I couldn't find any information on this bridge or on the other long bridges on Route 54D. It seems that the many amazing engineering achievements in Mexico get little publicity outside their borders.
Mexico's Bridges: Viaduct Beltran (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.
I like this picture. It shows in my opinion an important typical shortcoming of mexican bridges. To save money on the construction, where the costs often are based on squaremeters of superstructure, pedestrian sidewalks are nearly always omitted. And we're talking about a country where a lot of people walk from one village to another to get to work (or use bicycles). If you take a close look at the picture you can see a man crossing the bridge. In this case, like in most cases in such a big country with inadequate infrastructure, the next crossing of the river means hours of detours.
ReplyDeleteEven urban vehicular bridges are being built without sidewalks. You can imagine how many people die on the streets in Mexico. I still don't know how the authorities keep allowing that and just ignore the basic necesities of the people. It's easy being a politician to forget about that when you cross the country in a SUV.
I recommend the movie "En el hoyo" (In the pit). I especially liked the commentary of a construction worker of the elevated highway in Mexico City: "Yeah, it's nice. However I think I`ll never get to use it on my bike."