Worlds Longest Bridges

The Longest Bridge In USA

2010-02-16T14:10:00.000-08:00

The Longest Bridge in USA - Lake Pontchartrain Causeway

The Longest Bridge in USA and the world is Lake Pontchartrain Causeway, a 23 3/4-mile causeway spans Lake Pontchartrain, and a great cantilever bridge rises over the Mississippi at New Orleans.

This Longest Bridge in America consists of two parallel bridges that are the longest bridges in the world by total length. These parallel bridges cross Lake Pontchartrain in southern Louisiana. The longer of the two bridges is 23.87 miles (38.42 km) long. The bridges are supported by over 9,000 concrete pilings. These two longest bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.

The 24-mi. toll causeway across Lake Pontchartrain in New Orleans was opened for traffic on August 30, four months ahead of schedule. This Longest Bridge Constructed of precast, prestressed concrete, the two-lane causeway is 16 ft. above the lake. It is straight and level from end to end except for three 25-ft. humps, to allow passage of small boats, and two double-leaf bascule spans of 75-ft. clearance for larger craft. The $27,600,000 causeway was constructed of 2,243 bents, 56 ft. apart. Precast deck slabs, each weighting 185 tons, were transported from shore by barge and were lifted into position on the bents by floating cranes. The two piles of the bents are hollow, prestressed-concrete cylinders, 54 in. in diameter and 90 ft. long.

Longest Suspension Bridge

2010-02-16T11:07:00.000-08:00

Longest Suspension bridge

Longest suspension bridge in the world holds three records: it is the longest, tallest, and most expensive suspension bridge ever built.

The longest suspension bridge discussed below, is located in Kobe and Awaji-shima, Japan. The cost to build the bridge was $4.3 billion. The authority who has the credit to build such a huge bridge is Honshu-Shikoku Bridge Authority.

Longest suspension bridge at the moment is Akashi Kaikyo Bridge. Japanese Engineers made wonders in 1998 by completing Akashi Kaikyo Bridge. At the moment the longest spanning suspension bridge in the world, the Akashi Kaiko Bridge stretches 12,828 feet across the Akashi Strait to link the city of Kobe with Awaji-shima Island. Not only this longest suspension bridge is long but also its exceptionally tall. The two towers of this suspension bridge stand at 928 feet, which is higher than any other bridge towers in the world.

Engineers had a challenge to design the bridge like that which would not block shipping traffic of The Akashi Strait which is a busiest shipping port. They also had to bear in mind the weather conditions in Japan, because this country experiences some of the worst weather on the planet. Windstorms whip through the Strait. Rain pours down at a rate of 57 inches per year. Hurricanes, tsunamis, and earthquakes rattle and thrash the island almost annually.

How did the Japanese engineers find solution to these problems in building this longest suspension bridge? They supported their bridge with a truss, or complex network of triangular braces, beneath the roadway. The open network of triangles makes the bridge very rigid, but it also allows the wind to blow right through the structure. In addition, engineers placed 20 tuned mass dampers TMDs in each tower. The TMDs swing in the opposite direction of the wind sway. So when the wind blows the bridge in one direction, the TMDs sway in the opposite direction, effectively "balancing" the bridge and canceling out the sway. With this design, the Akashi Kaikyo can handle 180-mile-per-hour winds, and it can withstand an earthquake with a magnitude of up to 8.5.
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Worlds Longest Bridges

2009-12-11T10:46:00.000-08:00

Worlds Longest Bridges

Here is the updated list of Longest Bridges in the World

1. Lake Pontchartrain Causeway

The Lake Pontchartrain Causeway, or the Causeway, consists of two parallel bridges that are the longest bridges in the world by total length.[2] These parallel bridges cross Lake Pontchartrain in southern Louisiana. The longer of the two bridges is 23.87 miles (38.42 km) long. The bridges are supported by over 9,000 concrete pilings. The two bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.

2. Hangzhou Bay Bridge

Hangzhou Bay Bridge (simplified Chinese: 杭州湾大桥; traditional Chinese: 杭州灣大橋; pinyin: Hángzhōu Wān Dàqiáo), is a long highway bridge with a cable-stayed portion across Hangzhou Bay of eastern China. It connects the municipalities of Jiaxing and Ningbo in Zhejiang province. At 35.673 km (22 mi) in length, Hangzhou Bay Bridge is the longest trans-oceanic bridge in the world, but it does not have the longest cable-stayed main span. It is also second in the world in overall length, with the Lake Pontchartrain Causeway in the United States being 2.8 kilometers longer. Construction of the bridge was completed on June 14, 2007, and an opening ceremony was held on June 26, 2007 to great domestic media fanfare. But the bridge was not opened to public use until May 1, 2008 after a considerable period of testing and evaluation. The bridge shortened the highway travel distance between Ningbo and Shanghai by 120 km (75 mi) from 400 km (249 mi) and reduced travel time from 4 to 2.5 hours.

3. Donghai Bridge

Donghai Bridge (simplified Chinese: 东海大桥; traditional Chinese: 東海大橋; pinyin: Dōnghǎi Dàqiáo; literally “East Sea Grand Bridge”) is the longest cross-sea bridge in the world and the longest bridge in Asia until Hangzhou Bay Bridge opened on 1 May 2008. It was completed on December 10, 2005. It has a total length of 32.5 kilometres (20.2 miles) and connects Shanghai and the offshore Yangshan deep-water port in China. Most of the bridge is a low-level viaduct. There are also cable-stayed sections to allow for the passage of large ships, largest with span of 420 m.

4. King Fahd Causeway

The King Fahd Causeway is multiple dike - bridge combination connecting Khobar, Saudi Arabia, and the island nation of Bahrain. A construction agreement signed on July 8, 1981 led to construction beginning the next year. The cornerstone was laid on November 11, 1982 by King Fahd of Saudi Arabia and Sheikh Isa bin Salman al-Khalifa of Bahrain; construction continued until 1986, when the combination of several bridges and dams were completed. The causeway officially opened for use on November 25, 1986.

5. Chesapeake Bay Bridge

The Chesapeake Bay Bridge (commonly known as the Bay Bridge) is a major dual-span bridge in the U.S. state of Maryland; spanning the Chesapeake Bay, it connects the state’s Eastern and Western Shore regions. At 4.3 miles (7 km) in length, the original span was the world’s longest continuous over-water steel structure when it opened in 1952. The bridge is officially named the William Preston Lane, Jr. Memorial Bridge after William Preston Lane, Jr. who, as governor of Maryland, implemented its construction.

6. Vasco da Gama Bridge

The Vasco da Gama Bridge (Portuguese: Ponte Vasco da Gama, pron. IPA: ['põt(?) 'va?ku d? 'g?m?]) is a cable-stayed bridge flanked by viaducts and roads that spans the Tagus River near Lisbon, capital of Portugal. It is the longest bridge in Europe (including viaducts), with a total length of 17.2 km (10.7 mi), including 0.829 km (0.5 mi) for the main bridge, 11.5 km (7.1 mi) in viaducts, and 4.8 km (3.0 mi) in dedicated access roads. Its purpose is to alleviate the congestion on Lisbon’s other bridge (25 de Abril Bridge), and to join previously unconnected motorways radiating from Lisbon.

7. Penang Bridge

The Penang Bridge (Jambatan Pulau Pinang in Malay) E 36 is a dual-carriageway toll bridge that connects Gelugor on the island of Penang and Seberang Prai on the mainland of Malaysia on the Malay Peninsula. The bridge is also linked to the North-South Expressway in Prai and Jelutong Expressway in Penang. It was officially opened to traffic on September 14, 1985. The total length of the bridge is 13.5 km (8.4 miles), making it among the longest bridges in the world, the longest bridge in the country as well as a national landmark. PLUS Expressway Berhad is the concession holder which manages it.

8. Rio-Niteroi Bridge

The Rio-Niteroi Bridge is a reinforced concrete structure that connects the cities of Rio de Janeiro and Niteroi in Brazil.
Construction began symbolically on August 23, 1968, in the presence of Queen Elizabeth II of the United Kingdom and Prince Philip, Duke of Edinburgh, in their first and thus far only visit to Brazil. Actual work begun in January, 1969, and it opened on March 4, 1974.
Its official name is “President Costa e Silva Bridge”, in honor of the Brazilian president who ordered its construction. “Rio-Niteroi” started as a descriptive nickname that soon became better known than the official name. Today, hardly anyone refers to it by its official name.

9. Confederation Bridge

The Confederation Bridge (French: Pont de la Confédération) is a bridge spanning the Abegweit Passage of Northumberland Strait, linking Prince Edward Island with mainland New Brunswick, Canada. It was commonly referred to as the “Fixed Link” by residents of Prince Edward Island prior to its official naming. Construction took place from the fall of 1993 to the spring of 1997, costing $1.3 billion. The 12.9-kilometre (8 mi) long bridge opened on 31 May 1997.

10. San Mateo-Hayward Bridge

The San Mateo-Hayward Bridge (commonly called San Mateo Bridge) is a bridge crossing California’s San Francisco Bay in the United States, linking the San Francisco Peninsula with the East Bay. More specifically, the bridge’s western end is in Foster City, the most recent urban addition to the eastern edge of San Mateo. The eastern end of the bridge is in Hayward. The bridge is owned by the state of California, and is maintained by Caltrans, the state highway agency.

11. Seven Mile Bridge

The Seven Mile Bridge, in the Florida Keys, runs over a channel between the Gulf of Mexico and the Florida Strait, connecting Key Vaca (the location of the city of Marathon, Florida) in the Middle Keys to Little Duck Key in the Lower Keys. Among the longest bridges in existence when it was built, it is one of the many bridges on US 1 in the Keys, where the road is called the Overseas Highway.