The world is currently on a seemingly crazy rush of building the tallest buildings on earth. The very idea, though just a frenzy & fantasy to most, is undoubtedly the reflection of the relentless strive of every nation towards displaying its pride, wealth, commitment & technology. The last 15 years have seen a massive inrush of buildings on a scale that could never have been even imaginable before. And unsurprisingly, this list is growing rather exponentially, with approximately 9 skyscrapers over 500m under construction right away. Though none of these will even challenge the current leader, the Burj Al Khalifa, a few iconic structures have been planned in the next few years that could put even the giant under shade.
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| Countries with buildings in the top 200 and buildings 300 m or taller under construction Countries with buildings in the top 200 Countries with buildings 300 m or taller under construction but no current buildings in the top 200 |
Prince Charles famously doesn't care for skyscrapers. He sees them as a vain attempt to assert masculinity, like a rock star with a cucumber down his trousers – or, as he puts it: "Trying to make them ever taller than the other person's building is surely taking the commercial macho into the realms of adolescent lunacy". Phallic icons or not, we're about to move into a new era of mega-tall buildings. George Efstathiou, a managing partner at the architectural firm Skidmore, Owings & Merrill, declares that "the age of the super-skyscrapers is starting again" . Considering the scale of the structures on the way, he could well be right.
But how high can skyscrapers be? Is the sky the limit?
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| Burj Khalifa, the tallest building in the world. |
David Scott, chairman of the Council on Tall Buildings and Urban Habitats (CTBUH) and principal at the New York-based engineering firm Arup, doesn't believe there is an absolute limit. "Mount Everest is essentially a pile of stone," he says. "You don't need a lot of technology to create it. Just a lot of money."Engineers and architects have always speculated about how tall skyscrapers could be. Frank Lloyd Wright designed a mile-high tower, the Illinois, to be built in Chicago. It was proposed in 1956. Most experts agree that the technology was there to build it at the time, but not the investment.But money isn't the only limiting factor. Elevator technology lags behind building technology, and one obvious issue is lift cables; if they had to raise a lift one mile, they would be far too heavy. In Burj Dubai, no elevator goes all the way from the ground to the top.There's also we frail humans to consider. If an express elevator – at speeds up to 25mph – went from the ground floor to the top, we could pass out due to changes in the air pressure.
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| Taipei 101, second |
Then there's the problem of building movement. Most skyscrapers can sway a few metres in the wind without tumbling down, but the people inside might feel uncomfortable, if not downright nauseous, especially on higher floors. So the tallest structures need sturdy central cores to anchor them. The Empire State Building in New York, and other skyscrapers of that time, had steel beams wrapped around their elevator shafts.The Burj Dubai has a "buttressed core", or concrete hub, with three wings spreading out to form a kind of tripod. When the wind blows against two of the wings, the third supports them. Taipei 101 has a 730-ton pendulum in the top of the building; the giant ball swings against the movement to keep the upper floors steady.
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| WFC, Shanghai, Third |
More difficult are natural disasters, particularly earthquakes that could topple a skyscraper. In areas of high seismic activity, such as California, strict building-codes are in place to protect against earth tremors. The most common defence is to use mass dampers – essentially seismic shock absorbers – made of giant springs or hydraulic systems that move in the opposite direction to the earthquake's oscillations.And today, there's the threat of terrorism. Tall buildings are a target because they are iconic, and because they contain so many people. Lessons have been learnt from the attacks on the World Trade Centre, which led to the collapse of the towers. More internal supports make collapse far less likely. Stairwells are made wider to aid emergency evacuation, and ventilation systems force smoke out rather than letting it spread upwards, as if in a chimney.
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| ICC, Hong Kong, Fourth |
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| Petronas Towers,Fifth |
But the fact is that there are hazards everywhere in life. And most experts agree that the benefits of skyscrapers outweigh the downsides. Bill Baker, chief structural engineer at Skidmore, Owings & Merrill, believes that building high is not only safe, but necessary to stop cities devouring green-belt land. "Urban density is good," he says. "Everyone uses public transportation, people walk to lunch. Look at the Sears Tower in Chicago. It has 4.4 million square feet – that's 100 acres on one city block."David Scott of the CTBUH agrees. "If you look at the holistic impact of tall buildings on urban living, they offer many benefits," he says. "Not only do they reduce things like car ownership, but they can use waste heat in winter to warm them, and they have the potential to generate more open spaces at ground level, as well as reducing suburban sprawl. In the case of London, it can either expand outwards or upwards."But George Efstathiou, the architect, perhaps has the real reason for our love of skyscrapers: "Tall buildings are a matter of ego. Tall buildings are a sign of success."
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| The Imperial towers, Mumbai, Tallest in India |
The tallest buildings on earth as on august 2010
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| Willis tower,USA,sixth |
The non-profit, international organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of "The Worlds Tallest Building" and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The council currently ranks Burj Khalifa as the tallest at 828 m.The CTBUH only recognizes buildings that are complete, however, and some buildings listed within these list articles are not considered complete by the CTBUH.
In 1996, as a response to the dispute as to whether the Petronas Towers or the Willis Tower was taller, the council listed and ranked buildings in four categories:
- height of structural or architectural top
- height of highest occupied floor
- height to the top of roof (removed as category in 2009)
- height to top of any part of the building.
On the race course
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| India tower |
Already a large number of buildings are on the way to completion, adding further chill to the competition. The tallest among these is in India, called the India Towers. Planned for completion in 2015, this Mumbai giant would become the second tallest in the world with a pinnacle height of 702m, only surpassed by Burj Khalifa. Mumbai has another project in the top 10, World One tower, which upon completion in 2013 would become the tallest residential building on earth. Fourth in the list is the Abraj Al Bait towers or the Mecca Royal Clock Tower. This complex , with its tallest tower standing at 601m, would house the tallest hotel on earth & have the largest floor area of all buildings. It will also house the largest clock on earth, dwarfing the Big Ben at five times its size, and would be visible from a whooping 25 kilometers away! Fifth in the list would be the One World Trade Center, at the site of the old WTC's, and would become the tallest in the Americas.
Up in the future
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| Mile high tower, Jeddah |
The future as always hold plenty, as man's aspire for heights continue to spear miles. The Mile-High Tower is a skyscraper proposed for construction in Jeddah,Saudi Arabia. At 1 mile (1,600m) tall, it would be the tallest building ever built. The US$13.6 billion project, the centerpiece of a planned community near the coast, is being proposed by Al-Waleed bin Talal’s Riyadh-based Kingdom Holding Company. But this gigantic project has already started experiencing problems such as soil stability & certain reports had suggested that it had been put on a hold, but the planners have put these rumors to a rest. This reminds of a much more ambitious project, not for the height, but for the time when it was planned.
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| the Illinois |
The Mile High Illinois, Illinois Sky-City, or simply The Illinois was a proposed mile-high (1,609 meters) skyscraper, envisioned by Frank Lloyd Wright in 1956. The design, intended to be built in Chicago, would have included 528 stories, with a gross area of 18.46 million square feet. Had it been built, it would be the tallest building in the world. though this kind of a project was technically feasible even then, a large number of constrains meant that it would never set into construction.
Rumors have spread about even a 2 mile high tower (sky city), that not has yet been planned. But one things for sure - such projects will continue to rise as long as man survives..
That WFC , Shanghai was a nex info!!
ReplyDeleten also the INDIA TOWER to be constructed..
well done..