Contra Costa County, California Bridges: Benicia Martinez Bridges across the Carquinez Strait

February 2014 (38.0415 Degrees, -122.12330 Degrees) Benicia Martinez Bridges

Some bridges that we recently viewed from Solano County make another appearance in Contra Costa County. The Benicia Martinez Bridges include a new segmentally constructed prestressed concrete box girder bridge that carries northbound I-680. Just behind it is the Southern Pacific Railroad Bridge composed of camelback Warren trusses, a lift span over the channel, and a deck truss approach. Behind the much lower railroad bridge is a tall deck truss bridge that carries southbound I-680.

Contra Costa County, California Bridges: Benicia Martinez Bridges across the Carquinez Strait by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Yuba County, California Bridges: Timbuctoo Road Bridges across Deep Ravine #1 and #2

October 2013 (39.21083 Degrees, -121.31083 Degrees) Timbuctoo Road Bridges

Timbuctoo Road crosses the Colusa Highway at the east end of the Yuba River Bridge (see Google Earth photo below). The road snakes back and forth northeast of the highway before recrossing it a mile to the east.  Pony truss bridges carry the road over deep ravines that cross the road.

Deep Ravine Bridge No. 1 (16C0010) is a 50 ft long Queen post truss bridge with timber and steel beam approach spans that was built in 1936. The approach span on the north (far) side was severely damaged a number of years ago and the bridge remains closed.

A Queen post truss has vertical members at the 1/3 and 2/3 points along the span that act in tension to carry the deck.

Deep Ravine Bridge No. 2 is somewhat longer, a 70 ft long Pratt truss with three vertical posts. This bridge was built in 1903 and remains in service (although with a sufficiency rating of only 21.8).

Having Deep Ravine Bridge No. 2 remain open is clearly of some importance. Since both ends of Timbuctoo Road are connected to the Colusa Highway, as long as one bridge remains open drivers can access both road segments. Maintenance crews do a good job of replacing the timber deck and making sure this 110 year old bridge remains in service.

Yuba County, California Bridges: Timbuctoo Road Bridges across Deep Ravine #1 and #2 by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Tokyo Prefecture, Japan's Bridges: Kuramae-Hashi Dori Bridges across the Edogawa

September 2013 (35.7337 Degrees, 139.8997 Degrees) Kuramae-Hashi Dori Bridges

Greetings from Tokyo, Japan. I featured bridges across the Sumidagawa and Arakawa during past visits and so on this trip I'm staying at a ryokan near Koiwa Station to photograph the bridges across the Edogawa.

Tokyo uses its big rivers like the Arakawa and Edogawa as green spaces filled with parks, baseball diamonds, and soccer fields in the middle of the densely populated city.

Unfortunately the Man-Yi Typhoon was blowing when we went out today to photograph bridges. The wind gusts kept stopping our forward motion and white caps were on the river. I did manage to capture these four Warren truss bridges (made up of equilateral triangles) before my wife convinced me to head back. The parallel span Kuramae-Hachi Dori Bridges were between identical railroad bridges across the Edogawa.

Tokyo Prefecture, Japan Bridges: Kuramae-Hashi Dori Bridges across the Edogawa by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Placer County, California Bridges: Foresthill Bridge across the North Fork of the American River (8)

November 2012 (38.922 Degrees, -121.039 Degrees) Foresthill Bridge

Continuing down the North Fork of the American River and back to the Foresthill Bridge. We can see the river (considerably diminished from the Ponderosa Way Bridge) on the right side of the above photo. According to the excellent website provided by Placer County and Quincy Engineering, the seismic retrofit consists of strengthening or replacing the truss members and providing buckling restrained braces that act as dampers to absorb energy and reduce the superstructure movement during the Design Earthquake.

Other work includes improving access to the underside of the bridge, removing the lead-based paint and repainting the bridge, widening the deck, etc. All of the repairs and improvements should be completed by the end of the year.

Placer County, California Bridges: Foresthill Bridge across the North Fork of the American River (8) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Placer County, California Bridges: Foresthill Bridge across the North Fork of the American River (7)

November 2012 (38.922 Degrees, -121.039 Degrees) Foresthill Bridge

In the photo above, I walked towards the bridge (on a hiking trail) until few trees blocked my path only to discover that I was now too close to fit the bridge into one photo. I tried taking a photo, moving the camera to the right, and taking another photo so I could stitch the photos together when I got home.
I used Adobe Photoshop to stitch four photographs together into a single panoramic view of the bridge (above). However, I'm not sure if this provides more information than a photo taken farther away from the bridge.
The American River has a North, Middle, and South Fork. In the Wikepedia Map below, we can see the North and Middle Forks come together (in Auburn) and then meets the South Fork at Folsom Lake. The Foresthill Bridge crosses over the North Fork just before it reaches the Middle Fork.

Placer County, California Bridges: Foresthill Bridge across the North Fork of the American River (7) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.

Osaka Bay Bridges: Minato Bridge (2)

I thought we'd take one more look at the Minato Bridge before we moved on.

It's a really big bridge, with the third longest center span of any truss bridge in the world (after the Firth of Forth Bridge that was built in 1890). Since the Minato Bridge was built in the 1970's, this record may be a reflection on the lack of interest in truss bridges in recent years.

Suspension, arch, and cable-stayed bridges increase in length and ingenuity every year. However, truss bridges are expensive to build, difficult to maintain, and limited in length.

However, the fact that cantilever trusses need no falsework, may make them the best choice in some situations.

Osaka Bay Bridges: Minato Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Osaka Bay Bridges: Minato Bridge

The Minato Bridge is a Gerber truss structure that spans between Sakishima Island and the Port of Osaka in Osaka Bay. The center span was brought to the site on a barge and lifted into place with winches attached to the cantilevered ends.

It is a double-deck bridge with side spans of 235 m and a center span of 510 m. The bridge is part of the Wangan Expressway and is just south of the Tempozan Bridge. It was built in 1974 for the Hanshin Expressway Public Corporation (HEPC) at a cost of 25 billion yen.

The seismic criteria for Japan has changed quite a bit since 1974 and so this bridge was retrofitted a couple years ago with isolation bearings between the decks and the floor beams and with buckling restrained devices for the towers. More information on the retrofit is at: www.idi.or.jp/tech/quarterly/idi37.pdf

Osaka Bay Bridges: Minato Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo's River Crossings: Tobu Railway Bridge

South of the Sakura Bridge is the Kototoi Bridge, a 150 m long,  three span steel girder bridge that was built in 1931.

South of the Kototoi Bridge is the Tobu Railway Bridge over the Sumida River. It is a three-span, continuous steel deck-truss. The Tobu Railway must use electric trains, since there is an overhead wire above the deck. The truss is supported on reinforced concrete two column bents and abutments. The truss is deep and stiff in order to support several locomotives. The bridge was completed in 1931. The Tobu Railroad has the longest privately owned railway line in Japan (114.5 km from Tokyo to Isesaki).

Tokyo's River Crossings: Tobu Railway Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Tokyo's River Crossings: Horikiri Railway Bridge

The Arakawa River has a small channel that flows into the Sumida River near the Suijin Bridge. Just north of this channel are two bridges crossing over the Arakawa River: the Shuto Expressway Bridge and the Horikiri Railway Bridge.

The Horikiri Railway Bridge is a viaduct that includes three camelback truss spans over the Arakawa River. The Arakawa is substantially wider than the Sumida, which is its tributary.  Consequently, bridges crossing the Arawaka are several spans long. The Horikiri Bridge is supported by squat, two-column reinforced concrete piers. It caries the Keisei Electric Railway Line that goes between Tokyo and Narita. The bridge was built in 1967.

Tokyo's River Crossings: Horikiri Railway Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Washington State Bridges: Ship Canal Bridge

We'll spend the next few days looking at bridges in the Seattle Area.

The Ship Canal Bridge carries I-5 over Portage Bay in northern Seattle. It was completed in 1961, a year before the opening of I-5. It is a 4429 ft long bridge that includes a six span (2294 ft long) double deck truss structure over the water. The top deck is 82 ft wide and carries eight lanes of two-way traffic. The bottom deck has four lanes that carry southbound traffic in the morning and northbound traffic in the afternoon. At almost 200' tall, it is a very impresive structure.

Washington State Bridges: Ship Canal Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.