Tuesday, October 9, 2012

Niigata, Japan's Bridges: Motoschirocho Bridge across the U River (2)

August 2007 (N37.3547° E138.5515°) Motoschirocho Bridge
Some views from under the Motoschirocho Bridge. The superstructure is composed of four girders and a lot of cross-bracing. Vertical pipes drain the bridge deck into the river (something we're not allowed to do in California).
Note the stoppers that restrict longitudinal movement of the spans. It's hard to see how they can be effective when there's a backwall the girders will bang into first! 

There are other stoppers on the bearings that restrict vertical and transverse movement.  In California we sometimes use stoppers to restrict movement for service loads and smaller earthquakes but design them to break off for larger earthquakes. It looks like Japan's bridges are designed to move for smaller earthquakes but to stop for bigger earthquakes.
Creative Commons License
Niigata, Japan's Bridges: Motoschirocho Bridge across the U River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

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