10. The Hangzhou Bay Bridge
9. The Bosphorus Bridge
8. Gateshead Millennium Bridge
Remember how we talked about imagination and technology making it possible? Well, our number 8 on the list, Gateshed Millenium Bridge, definitely is a merger of both. The bridge’s design was a result of contest announced in 1996 to design an innovative pedestrian and cycle bridge over the Tyne River. The requirements were that the bridge should allow for the passing of ships, should not block the view of other bridges and must not affect the cultural activities going on either bank. The winning design was surely one that had never been seen before. It is made up of two steel arches. They are perpendicular to each other and one acts as the deck for cycles and pedestrians. When the bridge needs to be moved the whole structure moves as one with one arch acting as counter-balance and eight motors whir into action pulling the deck-arch up, making way for ships. The bridge was completed in 2000 with a length of 126 m.
7. Millau Viaduct
At number 7, we have the tallest vehicular cable stayed bridge situated in France and completed in 2004. It was built at Tarn Valley to carry the A75 motorway south to Beziers. The highest point on this bridge falls just short of empire state building. If you ever travel on this bridge, be warned; your car will be suspended 271 meters above the valley. If you are wondering why take the risk of this tall bridge; it helps you save yourself from a four hour drive and almost a 100 km. The bridge has also helped in easing the traffic pressure of the area.
6. Octavio Frias de Oliveira Bridge
5. St. Anthony Falls Bridge
4. DeNeveu Creek Bridge
Materials matter a lot when it comes to building structures. Steel used in concrete gets corroded when it’s exposed to water and/or air. Although we have a remedy for that; coating the rebars with epoxy but scientists at University of Wisconsin-Madison have developed another solution to this problem. Meet the reinforcing matrix made from a novel fiber-reinforced polymer. Yes, a lot of science so let’s break it down; basically the material is non-metallic and will not corrode while it has the strength to be used in structures providing a longer life to the structures. This material was used in DeNeveu Creek Bridge which is a 40m long bridge along Highway 151 in Fond du Lac, Wisconsin. The payoff is the fact that this box girder bridge will not require any maintenance for at least 75 years compared to other bridges which require it within 30-40 years. The bridge completed in 2005 is well off without any repairs until 2080!
3. Oresund Bridge
Oresund Bridge is the link bridge between Denmark and Sweden. The bridge came up as a challenge for the engineers since it had to carry both train and cars while the bridge had to be joined with an immersed tunnel as well. The project’s cost was around $3 billion. The whole project can be divided into three major parts; the tunnel, artificial island and the cable stayed bridge stretching over 5 miles which ends on Swedish soil. The bridge is the longest cable stayed bridge for both cars and trains. Its towers are about 204 m high. The lower deck is for the railway while the upper deck is for cars.
2. The Akashi Kaikyo Bridge
Japan’s pride- The Akashi Kaikyo Bridge had to face quite some issues during its construction. With around 4,000 small island, Japan enjoys to be the most seismically active region. The bridge survived a 7.2 magnitude earthquake and was then re-designed during its construction phase to cater for some of the damage that had been inflicted. The rest of the construction went quite successful and without any interruptions. The bridge opened in 1998 with a span of 3.9 Km with towers about 283 meters high. The cables carry tensile forces of 132,000 tons. It also enjoys the award of being the longest span suspension bridge.
1. Chesapeake Bay Bridge-Tunnel
The number one spot has been taken by Chesapeake Bay Bridge tunnel. As the name suggests, it is composed of bridges and tunnels. It has a total span of 27.4 Km with majority of the bridge-tunnel structure being just above the water. There are 5,000 piers to support this bridge. The tunnels, 1 mile long, allow for the ships to pass while taking the traffic beneath the bay’s navigation area which then re-surfaces on to two man-made islands. In 1965 this masterpiece won the award of ‘Outstanding Engineering Achievement’ and was designated as ‘One of Seven Engineering Wonders of the Modern World’.
Post a Comment