Alameda County, California Bridges: San Mateo-Hayward Bridge across San Francisco Bay

June 1998 (37.592702 Degrees, -122.236089) San Mateo-Hayward Bridge

The San Mateo- Hayward Bridge (35 0054) includes a 37 span steel orthotropic structure on the west end of the Bay and a long concrete trestle structure on the east end of the Bay. The whole bridge got a seismic retrofit in the late 1990s and these photos are from when I went out to see the work on the steel portion. Concrete columns were wrapped in steel casings and big 'dog bones' with more piles were wrapped around the foundations. The concrete trestle was also retrofit and it was widened to six lanes in 2003 (to match the west half of the bridge).

Alameda County, California Bridges: San Mateo-Hayward Bridge across San Francisco Bay by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (5)

June 2011 (38.415 Degrees, 141.312 Degrees) Hiyori Bridge

Just one more photo of the Hiyori Bridge and then we'll move on to something new. It's reassuring that bridges performed so well during the March tsunami. If the bridge was designed for ground shaking and the superstructure was above the waves, there was very little damage. Even if the superstructure was overtopped by the waves, the girders usually stayed in place.

There were many stories of people whose lives were saved because they were able to get onto a bridge. Unfortunately, there were also some stories of people who were swept away as they tried to cross a bridge just as the waves overtopped the deck. However, a really tall structure like the Hiyori Bridge would provide a safe haven for anyone lucky enough to get to it before the tsunami arrived.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (5) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (4)

June 2011 (38.415 Degrees, 141.312 Degrees) Hiyori Bridge

Another photo of the Hiyori Bridge across the Onagawa River in Ishinomaki. Some people say this bridge is across the Kitakami River (or the Old Kitakami River) because the river splits in two near the coast. We already saw the Kitakami Bridge (with two lost spans) near the mouth of the Kitakami River so I think it's clearer and more accurate to call this the Onagawa.

Also, I said yesterday that the various ladders were to help paint and maintenance crews. Obviously, that was wrong. This bridge has never been painted.

It looks like I'm standing by some flood gates that were damaged during the tsunami. There was a lot of damage along the coast, but almost no damage to this bridge.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (3)

June 2011 (38.415 Degrees, 141.312 Degrees) Hiyori Bridge

Back to Ishinomaki and the Hiyori Bridge. Looking up at the top of a tower with various connections to the superstructure. Four fixed (pinned) bearings support the box girder vertically, two restrainers support it longitudinally, but what supports it transversely? Perhaps the two center bearings are some kind of wind dampers?

There's a lot of stairs and platforms for the maintenance and painting crews that look like they were designed for safety. I like the amorphous stains on the Corten steel soffit.

Japan's Bridges: Hiyori Bridge in Miyagi Prefecture (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.