Japan's Bridges: Tobu Viaduct near Port of Sendai, Miyagi Prefecture

June 2011 (38.266 Degrees, 140.973 Degrees) Tobu Toll Road

For the past week we've been making our way steadily north through the City of Sendai and Miyagi Prefecture. I've been switching between the main transportation corridors: the Japan Railway and Shinkansen Viaducts to the west (along the foothills), National Route 4 through the middle of the city, the Tobu Toll Road to the east, and the inland shipping channel (along the coast).

Today's photo is of the elevated Tobu Toll Road near the Port of Sendai. This route was remarkable during the March earthquake because it was just high enough to save the lives of hundreds of people trying to escape the tsunami while the portions of the roadway on embankment were the only seawall that stopped the waves, protecting thousands of homes from inundation.

The viaducts carrying the toll road suffered considerable damage due to ground shaking, and three months after the earthquake they were still replacing delaminated elastomeric bearings and jacking the steel girders back in place.

I like the concrete texture on today's piers, created by gluing strips of wood to the forms. The lack of regularity of the piers along the viaduct is not allowed on California bridges, but it's probably okay for this viaduct because the piers are so much stronger than the bearings, which were the weak link in the lateral load path.

Japan's Bridges: Tobu Viaduct near Port of Sendai, Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Tobu Toll Road at Nanakitagawa, Miyagi Prefecture

June 2011 (38.2645 Degrees, 140.9710 Degrees) Tobu Toll Road

Big, reinforced concrete box girder spans carry the Tobu Toll Road over the Nanakita River in Sendai. We are on the west frontage road (going north) looking under the toll road bridge at the east frontage road bridge (going south). Barely visible behind the east frontage road is a utility bridge. On the horizon is a bridge carrying Prefectural Route 10, which was severely damaged by the tsunami.

Japan's Bridges: Tobu Toll Road at Nanakitagawa, Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridge: Nagamachi Viaducts in Sendai, Miyagi Prefecture

June 2011 (38.2379 Degrees, 140.8938 Degrees) 

I spent an evening walking along the elevated high-speed rail viaducts between Sendai and Nagamachi Stations. There were similar expressway viaducts along the Bay in San Francisco but the residents didn't like them and after suffering damage during the 1989 Loma Prieta earthquake they were removed. This area is not as pretty as San Francisco's Marina District, but it is a nice quiet neighborhood disrupted by the viaducts. However, taking a high-speed train is a very pleasant way of getting from Sendai to Tokyo.

These viaducts were damaged during the March 2011 earthquake, but unlike the ones in San Francisco, they were simply repaired and returned to service. You can see that the upper level columns are wrapped in steel casings, but they remain susceptible to damage during the next earthquake. I think high-speed rail should be put below grade. That way the trains can be more quickly returned to service following earthquakes and it would be less disruptive to the people who live nearby.

Japan's Bridge: Nagamachi Viaducts in Sendai, Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.