The Longest Bridge - Akashi-Kaikyō Bridge

The Akashi-Kaikyō Bridge, also known as the Pearl Bridge, has the longest central span of any suspension bridge, at 1,991 metres (6,532 ft). It is located in Japan and was completed in 1998. The bridge links the city of Kobe on the mainland of Honshū to Iwaya on Awaji Island by crossing the busy Akashi Strait. It carries part of the Honshū-Shikoku Highway.

The bridge has three spans. The central span is 1,991 m (6,532 ft), and the two other sections are each 960 m (3,150 ft). The bridge is 3,911 m (12,831 ft) long overall. The central span was originally only 1,990 m (6,529 ft), but the Kobe earthquake on January 17, 1995, moved the two towers sufficiently (only the towers had been erected at the time) so that it had to be increased by 1 m (3.3 ft). 
The bridge was designed with a two-hinged stiffening girder system, allowing the structure to withstand winds of 286 kilometres per hour (178 mph), earthquakes measuring to 8.5 on the Richter scale, and harsh sea currents. The bridge also contains pendulums that are designed to operate at the resonance frequency of the bridge to damp forces. The two main supporting towers rise 298 m (978 ft) above sea level, and the bridge can expand because of heating up to 2 metres (7 ft) over the course of a day. Each anchorage required 350,000 tonnes (340,000 LT; 390,000 ST) of concrete. The steel cables have 300,000 kilometres (190,000 mi) of wire: each cable is 112 centimetres (44 in) in diameter and contains 36,830 strands of wire.

  Source:wikipedia.org

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Millau Viaduct - World's Tallest Vehicular Bridge

Millau Viaduct - World's Tallest Vehicular Bridge
The Millau Viaduct (French: le Viaduc de Millau, Occitan: lo Viaducte de Milhau) is an enormous cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France.

Designed by the structural engineer Michel Virlogeux and British architect Norman Foster, it is the tallest vehicular bridge in the world, with one mast's summit at 343 metres (1,125 ft) — slightly taller than the Eiffel Tower and only 37 m (121 ft) shorter than the Empire State Building.

The viaduct is part of the A75-A71 autoroute axis from Paris to Montpellier. Construction cost was around €400 million.

It was formally dedicated on 14 December 2004, inaugurated the day after and opened to traffic two days later.

The bridge won the 2006 IABSE Outstanding Structure Award.

The bridge’s construction broke three world records:

• The highest pylons in the world: pylons P2 and P3, 244.96 metres (803 ft 8 in) and 221.05 metres (725 ft 3 in) in height respectively, broke the French record previously held by the Tulle and Verrières Viaducts (141 m/460 ft), and the world record previously held by the Kochertal Viaduct (Germany), which is 181 metres (590 ft) at its highest;
• The highest bridge tower in the world: the mast atop pylon P2 peaks at 343 metres (1,130 ft).
• The highest road bridge deck in the world, 270 m (890 ft) above the Tarn River at its highest point. It is nearly twice as tall as the previous tallest vehicular bridge in Europe, the Europabrücke in Austria. It is slightly higher than the New River Gorge Bridge in West Virginia in the United States, which is 267 m (880 ft) above the New River. Only the bridge deck of the Royal Gorge Bridge in Colorado, United States (mainly a pedestrian bridge over the Arkansas River, occasionally also used by motor vehicles) is higher with 321 m (1,050 ft), and is considered the highest bridge in the world.

The Millau Viaduct consists of an eight-span steel roadway supported by seven concrete pylons. The roadway weighs 36,000 tonnes and is 2,460 m (8,100 ft) long, measuring 32 m (100 ft) wide by 4.2 m (14 ft) deep, making it the world's longest cable-stayed deck. The six central spans each measure 342 m (1,120 ft) with the two outer spans measuring 204 m (670 ft). The roadway has a slope of 3% descending from south to north, and curves in a plane section with a 20 km (12 mi) radius to give drivers better visibility. The pylons range in height from 77 m (250 ft) to 246 m (810 ft), and taper in their longitudinal section from 24.5 m (80 ft) at the base to 11 m (36 ft) at the deck. Each pylon is composed of 16 framework sections, each weighing 2,230 tons. These sections were assembled on site from pieces of 60 tons, 4 m (13 ft) wide and 17 m (56 ft) long, made in factories in Lauterbourg and Fos-sur-Mer by Eiffage. The pylons each support 87 m (290 ft) tall masts.

The enormous pylons were built first, together with intermediate temporary pylons which were in themselves a massive record-breaking construction project.

Remarkably, the entire length of deck surface (that is to say, the bridge itself, the actual kilometers of roadway) was slid out, into the valley, across the pylons from both sides.

This feat was achieved using hydraulic rams that moved the deck about 600 mm every 4 minutes, over the course of many days.

While the kilometers of roadway was being slid-out through space, it was supported by both the final pylons and the temporary pylons.

Only after the roadway was completely slid-out in to the final position, were the masts erected on top of the deck (that is to say, over the pylons). To be clear, the masts on top are not continuing elements of the pylons underneath, although they appear to be. The masts are separate constructions which were built on land, wheeled out to position only after the pylons and roadway were complete, raised (with difficulty), and emplaced.

The construction of the massive cable-stay system between the masts and deck then followed.

Finally, the massive temporary pylons in the valley were removed.

Construction began on 10 October 2001 and was intended to take three years, but weather conditions put work on the bridge behind schedule. A revised schedule aimed for the bridge to be opened in January 2005. The viaduct was inaugurated by President Chirac on 14 December 2004 to open for traffic on 16 December, several weeks ahead of the revised schedule.

The construction of the bridge was depicted in an episode of the National Geographic Channel MegaStructures series, as well as Discovery Channel's Extreme Engineering, both of which included time-lapse footage of the ultimate astonishing feat of sliding the roadway out over the valley, on to the plyons, to create the bridge.

Source: wikipedia.org, yawoot.com

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World's Largest Gorge - The Grand Canyon of the Colorado River

World's Largest Gorge - The Grand Canyon of the Colorado River
The Grand Canyon (Spanish: Gran Cañón) is a steep-sided gorge carved by the Colorado River in the United States in the state of Arizona. It is largely contained within the Grand Canyon National Park, one of the first national parks in the United States. President Theodore Roosevelt was a major proponent of preservation of the Grand Canyon area, and visited it on numerous occasions to hunt and enjoy the scenery.

The Grand Canyon is 277 miles (446 km) long, ranges in width from 4 to 18 miles (6.4 to 29 km) and attains a depth of over a mile (1.83 km) (6000 feet). Nearly two billion years of the Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. While the specific geologic processes and timing that formed the Grand Canyon are the subject of debate by geologists, recent evidence suggests the Colorado River established its course through the canyon at least 17 million years ago. Since that time, the Colorado River continued to erode and form the canyon to the point we see it as today.

Before European immigration, the area was inhabited by Native Americans who built settlements within the canyon and its many caves. The Pueblo people considered the Grand Canyon ("Ongtupqa" in Hopi language) a holy site and made pilgrimages to it. The first European known to have viewed the Grand Canyon was García López de Cárdenas from Spain, who arrived in 1540.


The Grand Canyon is a massive rift in the Colorado Plateau that exposes uplifted Proterozoic and Paleozoic strata, and is also one of the six distinct physiographic sections of the Colorado Plateau province. It is not the deepest canyon in the world; Kali Gandaki Gorge in Nepal is far deeper, nor the widest (Capertee Valley in Australia is about 1 km wider and longer than Grand Canyon) — but the Grand Canyon is known for its visually overwhelming size and its intricate and colorful landscape. Geologically it is significant because of the thick sequence of ancient rocks that are beautifully preserved and exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent.

Uplift associated with mountain building events later moved these sediments thousands of feet upward and created the Colorado Plateau. The higher elevation has also resulted in greater precipitation in the Colorado River drainage area, but not enough to change the Grand Canyon area from being semi-arid. The uplift of the Colorado Plateau is uneven, and the north-south trending Kaibab Plateau that Grand Canyon bisects is over a thousand feet higher at the North Rim (about 1,000 ft/300 m) than at the South Rim. Almost all runoff from the North Rim (which also gets more rain and snow) flows toward the Grand Canyon, while much of the runoff on the plateau behind the South Rim flows away from the canyon (following the general tilt). The result is deeper and longer tributary washes and canyons on the north side and shorter and steeper side canyons on the south side.

Temperatures on the North Rim are generally lower than the South Rim because of the greater elevation (averaging 8,000 ft/2,438 m above sea level). Heavy rains are common on both rims during the summer months. Access to the North Rim via the primary route leading to the canyon (State Route 67) is limited during the winter season due to road closures. Views from the North Rim tend to give a better impression of the expanse of the canyon than those from the South Rim.

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The Glass Bridge Construction of the Skywalk

The Glass Bridge Construction of the Skywalk began March of 2004 and is estimated to be completed by 4th quarter of 2006. Glass Bridge will be suspended 4,000 feet above the Colorado River on the very edge of the Grand Canyon. On May 2005, the final test was conducted and the stucture passed engineering requirements by 400 percent, enabling it to withstand the weight of 71 fully loaded Boeing 747 airplanes (more that 71 million pounds). The bridge will be able to sustain winds in excess of 100 miles per hour from 8 different directions, as well as an 8.0 magnitude earthquake within 50 miles. More than one million pounds of steel will go into the construction of the Grand Canyon sky walk..................

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Nasa Images Of Ramayana Bridge

NASA SHUTTLE IMAGES OF A MYSTERIOUS ANCIENT BRIDGE BETWEEN INDIA AND SRILANKACourtesy : NASA Digital Image CollectionThe recently discovered bridge currently named as Adam's Bridge made of chain of shoals, c.18 mi (30 km) long, in the Palk Strait between India and Sri Lanka, reveals a mystery behind it. The bridge's unique curvature and composition by age reveals that it is man made. The legends as well as Archeological studies reveal that the first signs of human inhabitants in Sri Lanka date back to the a primitive age, about 17,50,000 years ago and the bridge's age is also almost equivalent. This information is a crucial aspect for an insight into the mysterious legend called Ramayana, which was supposed to have taken place in tretha yuga (more than 17,00,000 years ago). In this epic, there is a mentioning about a bridge, which was built between Rameshwaram ( India ) and Srilankan coast under the supervision of a dynamic and invincible figure called Rama who is supposed to be the incarnation of the supreme. This information may not be of much importance ! to the archeologist s who are interested in exploring the origins of man, but it is sure to open the spiritual gates of the people of the world to have come to know an ancient history linked to

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Bridge Between Sweden and Denmark

This bridge is half under the water, for ships to pass and then again, it comes out on the other side.

This bridge is between Sweden and Denmark

In 1991, the governments of Denmark and Sweden agreed to build a bridge to connect the two countries across the Oresund Strait. The 16-kilometer-long Oresund Link between Malmo, Sweden (right), and Copenhagen, Denmark (left), was completed and opened to traffic in 2000. Denmark and Sweden were linked once more —7,000 years after rising sea levels accompanying the end of the Ice Age severed the dry-land connection between the two.

The Oresund Link has three main segments. On the Denmark side, the link begins with a 3,510-meter (2.2-mile) underwater tunnel. The tunnel emerges from the water onto a roadway on a 4,055-meter (2.5-mile) artificial island, Peberholm, which appears as a bright white shape to the south of the natural island in the scene. The cable-supported Oresund Bridge stretches 7,845 meters (4.9 miles) across the eastern part of the Strait toward Sweden, making a thin white line across the image.

Deep water appears dark blue, shallow water appears bright blue, vegetation appears green, and developed or paved areas appear white. Several white specks in the waters of the Strait are boats or ships.

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