Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (3)

March 2012 (38.769 Degrees, 141.507 Degrees) Koizumi Bridge

The Koizumi Bridge had been retrofit with viscous dampers to absorb energy and protect the superstructure during an earthquake. However, the bolted connections to the girders must have broken when the waves overtopped the bridge. The pit around the pier (in the photo below) suggest that some scouring of the foundations took place at this bridge, perhaps resulting in the loss of the midspan pier.

Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (2)

March 2012 (38.769 Degrees, 141.507 Degrees) Koizumi Bridge

The Koizumi Ohashi was a 182m long plate girder bridge on hammerhead bents with a 10.5m wide deck. It was composed of two sets of three continuous spans and built in 1974.

The tsunami must have been particularly strong at this location because the Koizumi Bridge not only lost its superstructure, but its pier in the center of the river is also gone.

Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (1)

March 2012 (38.769 Degrees, 141.507 Degrees) Koizumi Bridge

We are at the northernmost bridge I visited after the 2011 Tohoku earthquake and tsunami. I thought I had traveled into Iwate Prefecture, but our tour must have turned around at the last bridge in Miyagi Prefecture. You can see the Tsuya Railway Bridge that we looked at yesterday in the distance.

This is the Koizumi Bridge that carried Route 45 over the Tsuya River. One year later a temporary bridge still carries Route 45 over the river. Actually the temporary bridge looks pretty much like the old bridge that was washed away (see photo below).

This week's news was full of reports about the damage from Hurricane Sandy. I've investigated bridge damage after many tsunami and a few hurricanes and I would say the amount of damage from a really strong hurricane is worse. It seems like a tsunami kills more people though. Perhaps that's because we are better at anticipating hurricanes than tsunami.

Miyagi Japan's Bridges: Koizumi Bridge across the Tsuya River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Tsuya Railway Bridge (3)

March 2012 (38.769 Degrees, 141.507 Degrees) Tsuya Railway Bridge

A last few photos of the Tsuya Railway Bridge, which used to carry the JR Kesen-Numa line. The photo above shows the bridge at the Koizumi Railway Station that was also destroyed by the tsunami.

The photo above shows the eastern bridge abutment with slope paving and embankment that was also damaged by the tsunami.

Miyagi Japan's Bridges: Tsuya Railway Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Tsuya Railway Bridge (2)

March 2012 (38.769 Degrees, 141.507 Degrees) Tsuya Railway Bridge

Another view of the damaged Tsuya JR Railway Viaduct in Koizumi. This is one of the rare examples where the piers were damaged by the tsunami (in background).

Miyagi Japan's Bridges: Tsuya Railway Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Tsuya Railway Bridge (1)

March 2012 (38.769 Degrees, 141.507 Degrees) Tsuya Railway Bridge

The next location is in northern Miyagi Prefecture at the Tsuya River. There was a lot of damage at his location including to this railway. We'll take a closer look at the railway damage tomorrow.

Miyagi Japan's Bridges: Tsuya Railway Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: The Utatsu Bridge (3)

March 2012 (38.716 Degrees, 141.523 Degrees) Utatsu Bridge

A couple of interesting things about the Utatsu Bridge. It appears that there was some ground shaking damage to this bridge before the tsunami. This short, stiff column may have been damaged due to rotation of the hammerhead bent cap before the tsunami struck the mainland.

Also, the other end of the bridge (across the bay) didn't lose its superstructure. The two ends survived intact while the middle of the bridge was washed away as seen in the Google Earth photo below.

Miyagi, Japan's Bridges: The Utatsu Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: The Utatsu Bridge (2)

March 2012 (38.716 Degrees, 141.523 Degrees) Utatsu Bridge

A couple of interesting things about the Utatsu Bridge. The bridge was retrofitted with concrete casings around the bents and steel shear keys between the girders. Most highway bridges in Japan got a very thorough seismic retrofit after the 1995 Kobe earthquake. However, bridges in Japan (and in the United States) haven't been retrofitted for tsunami.

Miyagi, Japan's Bridges: The Utatsu Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: The Utatsu Bridge (1)

March 2012 (38.716 Degrees, 141.523 Degrees) Utatsu Bridge

Continuing north on Route 45 to the town of Utatsu at the north end of the bay, which was devastated by the tsunami. The Utatsu Bridge has a long I girder superstructure on hammerhead piers that carried Route 45 along the shore and over the river. The spans over the river seem to be okay, but the spans along the bay were washed away.

We'll take a closer look at this bridge tomorrow.

Miyagi, Japan's Bridges: The Utatsu Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: Sakuragawa Railway Bridge (2)

March 2012 (38.691, 141.488) Sakuragawa Railway Bridge    

Continuing north on Route 45 we drove past the Sakuragawa Railway Bridges that is shown on the blog for October 16th (we stopped to photograph this bridge at the end of our trip).

Miyagi, Japan's Bridges: Sakuragawa Railway Bridge (2) by Mark Yashisnky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: Bridges over the Hachiman River (2)

March 2012 (38.675 Degrees, 141.448 Degrees) Highway 221 Bridge

Continuing north on Route 45 we arrive back at the Hachiman River that was previously studied on October 16th. Most of the buildings were washed away except for their concrete foundations.

Miyagi, Japan's Bridges: Bridges over the Hachiman River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi Japan's Bridges: Oritachi Bridge in Minami Sanriku

March 2012 (38.647, 141.437) The Oritachi Bridge

Driving north from the Kitakami Bridge, Route 45 cuts inland before returning to the ocean in the Minami Sanriku District at Sakuragawa Bay. The entire district was damaged by the tsunami including at this location. 

The floodgates (behind the building in the photo below) were damaged and the area was inundated by the waves. The Oritachi Bridge was washed away (where a blue replacement bridge can be seen on the right side of the photo). The Oritachi Bridge was a two span precast girder bridge that was completed in 1992.

The last photo shows how the area looked immediately after the tsunami. The floodgates can be seen in the background and the Oritachi Bridge (minus the superstructure and approaches) is in the foreground.

Miyagi Japan's Bridges: Oritachi Bridge in Minami Sanriku by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: Kitakami River Bridge (9)

March 2012 (38.547 Degrees, 141.423 Degrees) Kitakami Bridge

A last few photos of the Kitakami Bridge. The truss spans that remained were still attached to HDPE-wrapped cable restrainers between the floor beams and the piers.

The photo below shows a plaque giving the dates for design and construction of this bridge. I wonder if the Ministry is planning on replacing it?  In the previous photos we saw construction equipment and activity just upstream.

Starting tomorrow, we'll head north on Route 45 to look at some more tsunami-damaged and repaired bridges.

Miyagi, Japan's Bridges: Kitakami River Bridge (9) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: Kitakami River Bridge (8)

March 2012 (38.547 Degrees, 141.423 Degrees) Kitakami Bridge

A few more photos of the damaged abutment on the Kitakami Bridge. Bridge owners are now wondering if it's possible to design seat-type abutments that can securely anchor the superstructure during tsunami.

Miyagi, Japan's Bridges: Kitakami River Bridge (8) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Miyagi, Japan's Bridges: Kitakami River Bridge (7)

March 2012 (38.547 Degrees, 141.423 Degrees) Kitakami Bridge

We saw in a previous blog how the truss spans had been scarred by debris carried by the tsunami. However as seen in the photo above the five southeastern spans remained on their piers and were still functional. The waves must have been higher and faster along the northwest shore where the spans were carried upstream. Note the damaged concrete shear keys, cable restrainers, and broken bearings on the abutment and pier.

The missing spans were originally supported on the bank that is  dry during low tide (see photo below).

Miyagi, Japan's Bridges: Kitakami River Bridge (7) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.