|August 2007 (37.343 Degrees, 138.482 Degrees) Aumegawa Bridges
After driving through the severely damaged Yoneyama Tunnels we arrived at the Aumegawa Bridges. These are two haunched, three-span, segmentally-constructed cast-in-place, concrete box girder bridges on very tall hollow, reinforced concrete piers. Like several other bridges in the same area, the superstructures moved enough during the 2007 Kashiwazaki Earthquake to break the fixed steel bearings. Since these bridges weren’t designed with ductile elements, the weakest member, in this case the steel bearings acted as fuses to protect the structure from more catastrophic damage. Jacking up these long, continuous superstructures is no easy task, and jacking them back transversely is also a lot of work, but it’s also one of the most common types of bridge damage that can occur during earthquakes.
Niigata, Japan's Bridges: Aumegawa Bridges on the Horukiru Expressway by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.