Tokyo, Japan's Bridges: Komatsugawa Bridges across the Arakawa

March 2012 (35.701 Degrees, 139.856 Degrees) Komatsugawa Bridges

The Komatsugawa Bridge is actually a pair of steel, box girder bridges that carry Route 14 across the Arakawa. The bridges were built in 1969, they're 2300 ft long, and they each carry three lanes in opposite directions. It looks like the bridges were being painted on the day I took this photo.

Tokyo, Japan's Bridges: Komatsugawa Bridges across the Arakawa by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Osaka Bay Bridges: Nishinomiya Harbor Bridge

Today, we are studying the Nishinomiya Bridge between the cities of Osaka and Kobe. As you can see, some of the concrete hammer-head piers were shattered during the Kobe earthquake. Apparently, there was not enough transverse reinforcement, although the near fault ground motion would have damaged most structures. It's a continuous, six-span steel, box girder bridge with haunched girders.

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

Osaka Bay Bridges: Namihaya Bridge

The shoreline of Osaka Bay is crowded with artificial islands. Consequently, hundreds of interesting-looking bridges are used to connect these islands and to cross the many rivers around Osaka Bay.

The Namihaya Bridge crosses at the mouth of the Shirinashi River just south of the Minato Bridge in Osaka. It is a long viaduct that includes a 580 m three-span continuous steel box girder bridge.

It is difficult to tell from this photo, but the Namihaya is the longest horizontally curved box girder bridge in Japan. The viaduct is 1573 m long with a haunched girder center span of 250 m. The superstructure is supported on large, single column reinforced concrete bents. Perhaps because land is so expensive in Japan, bridges are seldom supported on multi-column bents. The bridge is 11 m wide and serves as an evacuation route for the Taisho-naiko port area in times of disaster. It was completed in 1994.

It seems like all the bridges in Osaka Bay are painted either red, white, or turquoise. I wonder if there is some significance to the color or if they just look good on bridges?

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

Tokyo Bay Bridges: Aqua-Line Bridge

Tokyo Bay is really big and so considerable time and effort has been spent to get people and goods across the Bay. The biggest effort so far has been the Trans-Tokyo Bay Highway. A 4.4 km long elevated highway carries vehicles into a 9.6 km long tunnel under Tokyo Bay.  The project includes a giant ventilator shaft in the middle of Tokyo Bay to supply fresh air to the tunnel. The highway goes from Kawasaki City on the west side of the Bay to Kisaruzu City on the east side of the Bay.

We were taken to visit the project in 1994, a couple of years before it was completed. The steel box girder segments were made continuous after they were set onto the 'Y' shaped piers. Span lengths decreased gradually from the two 240 m center spans.

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

Seine River Bridges: Pont de l'Alma

The Pont de l'Alma is a continuous, two span box girder bridge with the girders haunched at the pier to resist the large moment. It is actually two parallel bridges that are connected by a walkway on the deck. Most of the other Seine River crossings are arch bridges, but the Pont d'Alma is a similarly unobtrusive structure that was built to enhance rather than obscure views of the surrounding city.

The current Pont d'Alma was completed in 1974 to replace a narrow bridge of the same name that was slowly settling due to scouring of the foundations.  The replacement structure was built with a 40 meter deep foundation at the central pier and with piles supporting the abutments.

The previous bridge was commissioned by Napoleon to commemorate a victory over Russia in the Crimea.  It was a three span stone masonry deck arch bridge with statues of soldiers from different regiments at each pier. The statue of a Zoave (North African) soldier, was taken from the original bridge and placed upstream at the central pier of the new bridge.

The Pont d'Alma has a long (110 m) span that crosses most of the river and a short (31.5 m) span near the Right Bank.  It is 42 meters wide, carrying four lanes of traffic in each direction along with walkways on the two sides and at the center.

Considerable effort was made to preserve the Pont des Invalides (just upstream) while the Pont d'Alma (similar in structure, ornamentation, age, historical significance, etc.) was quickly replaced when it was found to be deficient. Perhaps this was because the Pont des Invalides was repaired in the 19th century and widened in the 20th century.  The Pont d'Alma required both at the same time.

Seine River Bridges: Pont de l'Alma by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Seine River Bridges: Pont Charles de Gaulle

The next bridge downstream on the Seine after the Pont de Bercy is the Pont Charles de Gaulle.

This bridge is a steel box girder with a reinforced concrete slab cast on top. There are shear studs connecting the slab to the steel box so that they can act together in bending. The concrete slab is transversely prestressed so that it can span the 31.6 m (104 ft) superstructure width.

Its a four span bridge supported by seat-type abutments and elliptical caissons with oddly shaped steel bearings. Each superstructure segment was manufactured in a plant, brought to the site at night, welded to the previous segment, and then pushed out over the Seine. Perhaps the strange bearings allowed the superstructure to be pushed out with minimum friction. More likely they changed the bearings after construction was completed.

This bridge is 208 m (682 ft) long with spans of 55 m (181 ft), 84 m (276 ft), and 69 m (227 ft). It has wide sidewalks as well as four lanes for one-way vehicle traffic from the Left to the Right Bank.

The winning design was chosen through an international competition in the late 1980's and completed in 1996.  My feeling is that this design (by the architects Louis Arretche and Roman Karasinski) was chosen because its thin section and clean lines don't interfere with the view of the Seine and its surroundings.  

Seine River Bridges: Pont Charles de Gaulle by Mark Yashinsky is licensed under a Creative Commons Attribution 3.0 United States License.