Shanghai, China's Bridges: A2 Expressway Bridge at Longgang

Shanghai is on a peninsula with the Yangtze River (Chang Jiang) to the north and Hangzhou Bay to the south. Its about 100 km from downtown Shanghai to the end of the peninsula on the new A2 Expressway (a toll road). The expressway carries traffic onto the Donghai Bridge that goes 32.5 km into the Bay (to the Yang Shan Islands). If you continue another 600 km to the northeast (across the East China Sea) you'll reach South Korea and Japan.

About 8 km before the end of the A2 Expressway (and the beginning of the Donghai Bridge) is a tubular steel, tied arch bridge. It crosses over a canal but I don't know if this bridge was the most economical choice or maybe it was chosen because people in China really like arch bridges.

Shanghai, China's Bridges: A2 Expressway Bridge at Longgang by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Shanghai China's Bridges: Wuzhen Road Bridge (2)

A view from the deck of Wuzhen Road Bridge. As I've mentioned previously, I was impressed by how relaxed and happy people are in Shanghai.

There's a concrete block protecting the arch rib at the sidewalk. Someone has written on the block a phone number for people to call who want a fake identity card. There are too many people moving into big cities and so the government issues ID cards to try to prevent this migration.

Note that the bridge has a second, interior barrier rail to protect the arch ribs and hangers from errant drivers. The outside barrier rail is decorated with wrought iron and the sidewalk is decorated with tiles.

Shanghai China's Bridges: Wuzhen Road Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Shanghai, China's Bridges: Wuzhen Road Bridge

The next bridge upstream across Suzhou Creek is a single span through arch with tubular steel ribs.

The Wuzhen Road Bridge is about 60 m long and 20 m wide. Like the Xizang Road Bridge, it has ramps that carry vehicles onto the bridge and stairways that carry pedestrians from the quays onto the bridge.

Suzhou Creek has an interesting history. In 1842 China was forced to open up to foreign trade. Shanghai became a major port and Suzhou Creek was used to bring goods out from China's interior. The banks became heavily industrialized and the water polluted. In 1998 the City of Shanghai began a project to revitalize the area. There was significant new construction as well as work to preserve historic structures. Pollution was stopped and parks and entertainment facilities were built along the creek.

Shanghai, China's Bridges: Wuzhen Road Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License

Shanghai's Bridges: Lupu Bridge (4)

This is the view looking north at the Luwan District of Shanghai from the top of the eastern arch of the Lupu Bridge. Although the main arch is 550 m long, it is also part of a 3,900 m long viaduct. A long viaduct is necessary to bring the approach high enough so the arch bridge can avoid river traffic and also to allow traffic to speed above city streets on an elevated expressway.

Construction activity is going at a rapid pace under the bridge as Shanghai prepares for the 2010 World Exposition. Hopefully, all of the effort and money spent on this 'World's Fair' will bring rewards to the people of China and the people of Shanghai. My impression was that the sacrifices for last year's Olympics in Beijing were not sufficiently appreciated or of much benefit to the people of China. I guess such sacrifices are a part of the process of opening up Chinese society to the world.

I know for myself that in the past I was never invited to visit China as an engineer, while I was frequently invited to attend conferences during the great economic boom in Japan. Now, I'm often invited to attend conferences, workshops, and symposiums, and to talk to my Chinese peers.

This is the first bridge that I have shown with four different photographs on my blog. I guess the Lupu Bridge is a little like an elephant. It looks like a totally different creature, depending on where you are standing and what you are looking at.

Shanghai's Bridges: Lupu Bridge (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Shanghai's Bridges: Lupu Bridge (3)

Another view of the Lupu Bridge. This photo was taken from the manicured park on the east riverbank.

This bridge is a basket-handle arch, which means the two arch ribs are inclined towards each other. It makes the arch more stable and more resistant to transverse loads. The arches are supported by large pile caps that carry the dead load, live load, wind load, etc. and a portion of the thrusting action of the arches. However, tied cables and stiffened girders at the deck level carry most of the thrust.

It looks like a painter's traveler is tucked behind the arch under the deck. You can see the steel rails under the deck that support the traveler. A big expense of steel bridges is keeping them primed and painted. I'm not sure why the large ship is parked under the bridge unless it is also used to help maintain the bridge.

Shanghai's Bridges: Lupu Bridge (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Shanghai's Bridges: Lupu Bridge (2)

A few kilometers upstream from where yesterday's photo was taken is the Lupu Bridge. This is the bridge I showed when I started my blog on January 26, 2009.

The City of Shanghai had to design and build the world's longest arch bridge in order to cross the wide Huangpu Bridge. While a cable-stayed or suspension bridge can easily span 550 m, this is currently the maximum length for the main span of an arch bridge. However, a bridge in Dubai with a main span of 667 m will be completed in 2012.

The Lupu Bridge is a three span, half-through, tied-arch design. This type of arch bridge was chosen because the soft soil wouldn't be able to support the large thrust of a through arch. Temporary towers were built to support each side of the arch with cables until the final segment joined the two halves together. Cable ties at deck level carried the thrusting action of the arch. The tension in the cables was adjusted before and after the orthotropic deck was built. A good report on the design and construction of this bridge was written by Yue Guiping of the Shanghai Municipal Engineering Design General Institute.

Shanghai's Bridges: Lupu Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.