10 Pontes estruturalmente impressionantes no Mundo

10 Bridges structurally impressive in the World

1 - Hangzhou Bay Bridge

At 36 km, the Hangzhou Bay Bridge is the longest in the world, being understood from one side to another of the Qiantang River

The Chinese are not new in the construction of bridges. The Anlan bridge, suspension bridge built for the first time in 300 BC using bamboo cables, still carries pedestrians by 305 meters that separate one from the other bank of the river Min [source: New]. More than 1,700 years later, in Jiangsu Province, Chinese engineers have completed a project that includes a pole drop of 1,490 meters long, and a cable-stayed bridge of 758 meters. Known as Runyang Bridge was the longest bridge in the country for a while.
Today, the Hangzhou Bay Bridge, which opened in May 2008 after nine years of planning and construction, holds the title of longest bridge in the world. It stretches for 36 km from side to side of the Qiantang River at the Yangtze River Delta in East China Sea. It is almost 25 times longer than the bridge Runyang and 9 times longer than the pride of Japan, the Akashi Kaikyo Bridge. The cable-stayed bridge in China snaking across the open sea, carrying six lanes of traffic in both directions. The daily have to pay 80 yuan, or nearly $ 20, to cross it, but the toll is nothing compared to the price of building the bridge - 11.8 billion yuan ($ 1.72 billion). If it lasts as much as expected - 100 years - there will be enough time for her to pay.

2 - Bosphorus Bridge

The Bosphorus Bridge in Istanbul Strait, connects Europe to Asia

The Bosphorus Strait, also known as the Istanbul Strait, connects the Black Sea and the Marmara Sea. It also separates Asia from Europe. As such, it has great strategic value during times of war and peace. Although attempts to connect the bridge with a narrow strip of water date back to the Persian Empire, the most impressive structure was not inaugurated until 1973. That's when engineers completed the Bosphorus Bridge, a large suspension bridge 1.51 km which remained the only bridge in the world linking two continents by Fatih Sultan Mehmed Bridge suspended over a narrow highway about 15 years later.
Even with a bridge partner stealing a little of his glory, the Bosphorus Bridge is still a great view, especially at night. Thanks to LED lighting, the towers and cables zigzag bridge glow in different colors.
Day or night, the Bosphorus Bridge carries traffic between the two continents on a track with eight lanes. Each direction has three lanes for vehicles, plus one emergency and one for pedestrians. Pedestrians could access the bridge until 1977, when they were banned by the authorities for security reasons. In May 2005, this rule was suspended temporarily when Venus Williams and Ipek Senoglu played a game of tennis on the bridge to promote the opening of the World Cup in Istanbul, Turkey. Fans gathered in the two lanes of the bridge to watch the exchange of volleys of players from Asia to Europe and vice versa.

3 - Gateshead Millennium Bridge
A Gateshead Millenium, na Inglaterra, usa um inovador sistema de inclinação para deixar passar navios, pedestres e ciclistas
The Gateshead Millenium, England, uses an innovative tilt system to let ships pass, pedestrians and cyclists

In a bascule bridge, one or two pieces of the bridge deck, known as leaves, ranging up to offer passage to boat traffic under it. They open quickly and effectively, but are not the most elegant pieces of architecture. That was the challenge that lay ahead when engineers authorities of Gateshead, England, announced a competition in 1996 to design a bridge for pedestrians and cyclists over the River Tyne innovative. The new structure had to allow ships to pass under the bridge without blocking the view of other nearby bridges or interfere with cultural activities that take place on both sides of the river.
The winning design solved the problem, not with a system like trucks, but with a tilt mechanism never seen before. Here's how it works. The bridge is made of a pair of steel arches. In its low position, an arc forms the deck of the way of pedestrians and bicycles. The other arc is at a 90 degree angle to the first, with wires strung between the two to provide support for the platform. When the bridge needs to be moved upwards eight electric motors incline the two arcs like a single rigid structure. While a bow falls, the other rises to act as a counterweight.
When the bridge of 126 m extension was opened in 2000, 36 000 people were lined up on the banks of the Tyne to attend the inaugural tilt. And in 2007, his portrait appeared on the new £ 1 coin minted by the royal treasury.

4 - Millau Viaduct

The Millau Viaduct is the highest vehicular bridge in the world, she crosses the Tarn Valley, France; providing one of the most stunning aerial images of the planet

The Eiffel Tower, which looms over Paris, measures 324 meters in height, the walk to the tip. Now imagine wrest it from its foundations and upload it to the southeast, through the Massif Central region of France until the Cevennes Mountains. Now imagine putting the tower in the Tarn Valley, a deep canyon surrounded by high hills and undulating near the town of Millau, France. Now, finally, view equivalent to six towers Eiffel aligned, forming a trail across the valley. Ready: You have the Millau Viaduct, a massive bridge opened in 2004 which carries the A75 road south of Beziers.
In fact, the highest point of this cable-stayed bridge is 19 meters taller than the Eiffel Tower and only slightly lower than the Empire State Building (with 381 meters high). A car traveling on the central span of Millau is actually suspended 271 meters above the valley. Drivers who overcome their fear of heights can save 100 miles and 4 hours of a long trip from Clermont-Ferrand to popular destinations along the Mediterranean Sea. The bridge also reduces pollution by relieving congestion that used to occur while the cars formed lines to cross a bridge much older and small in Millau.

5 - Bridge Octavio Frias de Oliveira

The two-lane cable-stayed bridge in the X Octavio Frias de Oliveira in Sao Paulo, are suspended by 144 cables

São Paulo, Brazil, is known for his exuberance. It is a cosmopolitan city with a bustling nightlife and cultural scene dynamics. It is also the financial center of Brazil - home to some of the wealthiest people in the country. Because of these qualities, it is not surprising that paulistanos draw bridges and build one of the most exceptional in the world.
Named after the proprietor of communications Octavio Frias de Oliveira, the cable-stayed bridge passes over the Pinheiros River, which cuts through the west side of town. The bridge is only 900 meters long and is not particularly high (138 meters), but its design features two curved decks that cross the X-shaped tower that supports the bridge. The two-lane bridge, suspended by 144 cables in the tower, connecting the neighborhoods of Brooklyn and Park Royal.
Motorists crossing the bridge at night you can enjoy a spectacular show of LED lights. The lighting system allows administrators to illuminate the bridge X-shaped tower with different colors for holidays and special events, But it is not just special effects. A series of light bulbs of 140 watts roads to ensure the safety of motorists.

6 - St. Anthony Falls Bridge

The St. Anthony Falls bridge is made of concrete and has high performance embedded sensors that indicate any structural changes

In August 2007, the steel frame of the deck of a bridge carrying motorists into and out of Minneapolis fell into the Mississippi River during rush hour at the end of the day. An investigation revealed that the 16 junction plates that connected the iron beams span the central support columns were too thin to function properly. As a result, they broke and caused the collapse of the bridge. Within hours, the authorities promised to rebuild the bridge, and to restore public confidence, incorporate a variety of advanced security features. The result was the St. Anthony Falls Bridge, which opened in September 2008.
This hollow section bridge is a marvel of modern engineering. It is made with high-performance concrete, strong and corrosion resistant. More than 6.8 million pounds of steel bars - all covered with epoxy to prevent the concrete from cracking or fade - reinforce concrete. At the same time, 323 sensors embedded in the substrate of the bridge constantly monitor the integrity of the structure, collecting data that can be analyzed to determine points of unusual stress or other trouble spots. Although forms a solid foundation, the concrete is also cleaning the air. This is because it is made from cement containing TX Active, an agent that in presence of light, air dissipates pollutants including carbon monoxide, nitrogen oxide and benzene.
High-tech materials such as TX Active are becoming commonplace in modern bridges. One such bridge is located west of Minneapolis in Fond du Lac, Wisconsin.

7 - Bridge Creek DeNeveu
A ponte DeNeveu Creek foi construída com matrizes de reforço plásticas reforçadas
The bridge was built with DeNeveu Creek matrices reinforced plastic reinforcement

Specifically, a combination of hard and porous cement, sand, gravel mass and forms the foundation of most bridges. It well withstands compression forces (those that push down under certain angles), but not as good tensile forces / traction (those which act along the length of the material to tear it). Engineers use steel bars, also known as rebar, to increase the tensile strength of concrete.
Unfortunately, the reinforcement bars can corrode when exposed to water (fresh or salt), which may cause damage to the concrete. One method to avoid this is to cover the wear reinforcement bar with epoxy, forming a shield in the steel against corrosive substances. But scientists at the University of Wisconsin-Madison developed another solution - an array reinforcement made of a new fiber reinforced plastics. Since it is not metal, the plastic material is not corroded, which means that the concrete remains stronger longer.
The first test in the real world this is the new improved concrete DeNeveu Creek Bridge, a span of 40 meters along Highway 151 in Fond du Lac, Wisconsin. Driving over the bridge you ever notice anything special hidden inside the hollow section indescribable. But the real gain will be the future. The deck of the bridge lasts at least 75 years, while the traditional decks of bridges last between 30 and 40 years before needing to be replaced. This means that the DeNeveu Creek Bridge, completed in May 2005, may not need significant maintenance until 2080.

8 - Oresund Bridge (Øresundsforbindelsen, Öresundsförbindelsen)

Oresund Bridge is a miracle of modern engineering; carries trains and cars under and over the Oresund strait between Denmark and Sweden

Bridging specific use is a complex engineering feat. Now add other factors more complicated, like a bridge carrying both cars as trains. And add to that discreetly bridge an underwater tunnel. These were the design requirements that engineers had in hand when they began planning how to connect Denmark to Sweden via the Oresund Strait. His solution was one of the largest infrastructure projects in European history: the Oresund Fixed Link, which cost $ 3 billion [source: Lundhus].
The Fixed Link actually consists of three major parts. If you are traveling from Copenhagen to Malmö, Sweden, the first thing you see is an underwater tunnel of 4 km. Back at sea level, you emerge from the tunnel on Peberholm, an artificial island built of discarded material during construction. After Peberholm, you access the final leg of the Fixed Link, a cable-stayed bridge that stretches for 8 km and ends on Swedish soil.
Collectively, the Oresund Fixed Link is a miracle of modern engineering. She is the longest cable-stayed bridge in the world for cars and trains [source: Oresund Bridge Web site]. Its towers are 204 meters tall and provide visibility navegaçãp of 57 meters under the main span. The bridge has two levels, with the railroad tracks running along the lower deck and the freeway, on the top deck.

9 - Bridge Akashi Kaikyo
Ponte Akashi Kaykio, a mais longa do mundo
Akashi Kaykio Bridge, the longest suspension bridge in the world

Japan is the dream and the nightmare in building bridges. Comprised of four main islands and 4,000 smaller islands, Japan is a true vein of options and opportunities for crossing bridges. Unfortunately, Japan is located on the Ring of Fire, an area where a large number of hurricanes and volcanic eruptions occur. This makes the construction of large structures supreme engineering challenge. With the bridge Akashi Kaikyo, Japanese engineers were ready for the challenge.
The Akashi Kaikyo Bridge opened in 1998 and shocked the world with its epic size. It stretches for 3.9 km over the Akashi Strait, with a central section measuring almost half that length. Its towers rise 283 meters above the water, and their cables sustain tensile forces of 132 tons. She is not only the highlight of the elaborate system of bridges in Japan, it is also the longest suspension bridge and the tallest towers in the world. The Akashi Kaikyo makes it even more impressive is the fact that she had been battered by an earthquake of 7.2 on the Richter scale during its construction. The quake happened on January 17, 1995, creating a new fault near the bridge. This raised the foundations and expanded the central span of the bridge 80 cm and a side span almost 30 cm. Fortunately, the earthquake did not damage the towers. The engineers increased the length of the cables, beams redesigned to accommodate the increased length and continued without any further mishap.

10 - Bridge-Tunnel Chesapeake Bay
Os dois vãos da ponte da Baía de Cheasapeak, um complexo de túnels, ferrovia e rodovia
The two spans of the Bay Bridge Cheasapeak, a complex tunnel, rail and road

Two bridges span the Chesapeake Bay, a long estuary sandwiched between the states of Virginia and Maryland, USA. The first is the Chesapeake Bay Bridge, a bridge will double to 6.97 km in length that connects the east and west coasts of Maryland. Although this bridge offers a collection of interesting designs in a unique structure - cantilever, arch and suspension - it is a bit overshadowed by his cousin located a few miles south. The official name of this second bridge is Bridge Tunnel Lucius J. Kellam Jr., more commonly known as Bridge-Tunnel Chesapeake Bay.
As its name suggests, the link consists of a series of bridges and tunnels that cross the 27.4 km brackish water separating Cape Charles and Virginia Beach, Virginia. Most of the complex bridge-tunnel is above the water supported by more than 5000 pillars. Most of these columns is relatively short, so the bridge looks at the planar surface of the water. To allow the passage of ships, two tunnels of 1.6 km long carry traffic underneath the main navigation channel of the bay. Man-made islands, each having approximately 20 square meters, are located at the end of each of the two tunnels and act as transition points between the tunnels and bridges.
When the original bridge-tunnel complex (the side that leads to the north) opened in 1965, won the American Society of Civil Engineers Award for "Outstanding Achievement in Engineering." She was also named one of the "Seven Wonders of Engineering of the Modern World" in 1965. Thirty years later, engineers began construction of a second link (the side that leads to the south), which was opened for traffic in 1999.

Source: discovery.com


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