Bridges around the world are some of the best gift of civil engineering. Bridges are a necessity built by humans in order to cross barriers. They join pieces of land which are otherwise time consuming and dangerous to be reached. From small to large, short to tall every bridge has its own importance. The very first bridges in the world were from plant roots, tree trunks, ropes and wooden planks. Then the usage stone for bridges became popular. But this was not a long term solution to overcome the obstacles of nature. The man in the modern era came with more viable materials like iron, concrete and steel. Apart from the materials used and right design, intelligent engineering and advance skills play a vital role in the construction of a successful bridge. Pushing over the limits and crossing the boundaries of nature these are the ten iconic bridges that are a result of intelligent engineering.
- GARABIT VIADUCT
Garabit Viaduct is a single track arch train bridge designed by Gustave Eiffel. The construction of the bridge started in the year 1882 and has been in use since 1885. This 552 m long and 124m high bridge is in the Cantal region in Southern France over the river Truyère. The bridge has 7 piles and a 165m stretched parabolic arch in the centre. It was built to link Paris with Beziers. When the bridge was completed it was the tallest bridge in the whole world. An interesting fact about this bridge is that the famous girders by Gustave Eiffel were patented during the construction of the bridge. These girders were later used in the Eiffel tower. The bridge was carefully designed to give enough space for wind to pass through. Rivets were used to assemble the wrought iron girdles used in the bridge. The bridge revolutionized the field of civil engineering.
- THE BROOKLYN BRIDGE
The Brooklyn Bridge is a suspension bridge bridging over the East River from Brooklyn to Manhattan in the New York City. Brooklyn Bridge became the first bridge to use galvanized steel after realizing the drawbacks of iron. Other materials used in the bridge were limestone, granite and cement. The Brooklyn Bridge was a design of John Augustus Roebling, but unfortunately after his death, his son and daughter in law Washington Roebling and Emily Roebling respectively took over its construction. It is the result of their endeavor that this 1825m across bridge stands tall today. The Construction of the bridge started in the year 1870 and after sheer hard work of the Roebling family and the worker, the bridge was completed in 1883. When the bridge was under construction once its foundation sunk in the east river. This was one of the few hurdles the bridge faced in its making. The bridge used two 50 m by 30m wooden caissons, with boxes of granite for the tower laid on it and compressed air was injected into the boxes. This has not been done before. After the towers rose towers the sky, the steel cables were installed on it. Four main cables supported the deck.
- FORTH BRIDGE
Crossing the forth of Firth in Scotland and covering a distance of nearly 2.5 km, the Forth bridge is a cantilever bridge built in the year 1890. In fact, it is the most famous and longest single cantilever bridge in the whole world. Construction of the bridge began in 1882 and 8 year later on March 4, 1890 it was ready to be used. The bridge is a vision of two innovative engineers Benjamin baker and Sir John Fowler. Four granite foundations support its three main towers. The rail bridge reduced the rail distance between London and Aberdeen. The bridge uses 50 thousand tons of steel and 6.5 million rivets in its making. It is also declared a World Heritage Site by UNESCO .
- RIO ANTERIO BRIDGE
The Rio Anterio Bridge was inaugurated in august 2004 after 7 years of construction in the Gulf of Corinth in Greece. The bridge connects the Peloponnese to the Greek mainland. It has four pylons made from reinforced concrete. The bottoms of the pylon are up to 45m high and head of the pylon is about 160 m above the sea level. The base of the piers is made up of caissons. Seabed reinforcement was absolutely necessary as the bridge is in a high seismic activity area. 25m long hollow pipes of 2m diameter were directed into the seabed to achieve seabed reinforcement. The 2340 m bridge has survived the 2008 earthquake and is absolutely safe to be used.
- MILLAU VIADUCT
Available to be used by the public in December 2004, Millau Viaduct is the largest cable stayed bridge in the entire Europe. The 2.4km long bridge is 270m above the sea level stretches across the Gorge valley, over River Tarn in Millau. The purpose for building this bridge was to reduce traffic jams in Millau. As it covers such a long distance, the bridge uses seven pylons instead of two or three which is usually the case. The Millau Bridge is also not a straight but is curve to avoid the sensation of floating for the people passing through it.
- VASCO DA GAMA BRIDGE
Europe’s longest bridge, the Vasco da Gama Bridge is 17,185 m long spanning over Tagus River in Parque das Nações in Lisbon, the capital of Portugal. The construction of this cable-stayed bridge began in February 1995, and it was opened on March 29 1998. Expo 98, the World’s Fair celebrating the 500th anniversary of the discovery of the sea route to India by Vasco da Gama, was right on schedule when the bridge was inaugurated. The bridge is designed to withstand strong winds and high magnitude earthquakes. There are 6 road lanes on the bridge and as a safety the speed limit on the bridge is set to be 120km/h.
- WASHINGTON BRIDGE
World’s busiest bridge, the Washington Bridge is a 724 m long arch bridge over the River Harlem in the New York City. The terminals of the bridge connect the University Avenue in Morris Heights, Bronx with 181st Street and Amsterdam Avenue in Washington Heights, Manhattan. The work on building this bridge began in July 1886 and by 1888, the bridge was well in use. It was once the longest suspension bridge in the world. Six lanes and two sidewalks make this bridge complete. The construction of the Washington Bridge was acknowledged as an architectural accomplishment of New York City.
- GOLDEN GATE BRIDGE
Stretching across 1.6 km long above the Golden Gate strait that connects San Francisco Bay and the Pacific Ocean, the Golden Gate Bridge is a suspension bridge. First opened in 1937, it is the 7th largest suspension bridge in the world. The Vermilion color of the bridge compliments with the scenery and due to high wavelength the bridge can be seen by ships even in foggy days. It also prevents the bridge from corrosion. The Bridge is known to be a symbol of power and progress in the United States.
- AKASHI KAIKO BRIDGE
Over the Akashi Strait in Japan stretches a 3,911 m long Akashi Kaiko Bridge. Also referred to as the Pearl Bridge, it has a six lanes, and the bridge is divided into three span. Some of the greatest challenges in a bridge’s construction and sustainability are the distance it has to cover, the height it has to reach and the hard conditions it may be subjected to. Akashi Kaiko had to face it all. The bridge is constructed in a very seismically active zone and has experienced some of the greatest earthquakes. It is designed with uniquely innovative and upgraded wind-tunnels and cable fabrication technology which will enable the bridge to withstand heavy winds, typhoons and earthquakes.
- ORESUND BRIDGE
The Oresund Bridge is a three section bridge consisting of a bridge, an artificial island and a tunnel. The cable-stayed bridge spans 7845m across the Flinte Channel acting as a link between Sweden and Denmark. The bridge itself is divided into two levels: the railway running in the lower deck and the roadways on the upper deck. The bridge was opened to public traffic on July 1, 2000. The artificial island called the Peberholm was made from the dredged material from the Oresund seabed. In this section the railway and the roadway run parallel to each other. The 4km underground tunnel is built using concrete and is well equipped with emergency exits, telephones, fire extinguishers and alarms. The construction of the Oresund Bridge involves strategic engineering and hard work of 6 years makes this bridge so special.
