The very height of ambition

I think someone may have already posted this one? Don't remember seeing it though?





An Australian surveyor working on the world's tallest building has faith that, despite challenges, it will work, writes John Huxley.

IT WAS during faraway days spent playing make-believe games, building cubby houses in the bush near his childhood home in Bridgetown, Western Australia, that Ian Sparks decided his future lay in construction. "I've always thought, 'Yeah, I can make this, I can build that,"' he recalls.

Little did he imagine that more than half a century later he would be working at the top of his profession - quite literally - as project surveyor on what will be, for several years at least, the world's tallest building: Burj Dubai - the "Tower of Dubai".

As Andres Lepik, author of Skyscraper, notes, the tower could easily have been built in Australia. Its design is based on that of Harry Seidler for the Grollo family. However, his plans for a heavenly, 500 metre high-rise to be built in Melbourne, were rejected by authorities in 1999.

Instead, the proposed tower has been refurbished, stretched and is set to rise like a dazzling, cut-diamond rocket, like steepling concentric slivers of concrete, steel and glass, above the old town, in the United Arab Emirates capital, amid an explosion of superlatives.

According to the Korean contractor Samsung, it will be a shining symbol of the new Middle East. A beacon of progress for mankind. An embodiment of the world's highest aspirations. And, of course, the tallest of the latest generation of supertall structures.

No one - certainly not Sparks - will say officially how high the $1.1 billion Burj Tower will be when topped out in 2008: to do so would only alert potential competitors even now drawing up plans to outstrip Dubai, he says.

Industry insiders, however, expect the building, which includes a hotel, shopping mall, offices and luxury apartments, will have more than 160 storeys and rise to more than 800 metres: easily dwarfing the present world's highest building, the 508-metre TFC 101 Tower in Taipei, Taiwan.

Sparks has a head for heights: he also worked with Samsung as project manager on the 88-storey Petronas Twin Towers, in the Malaysian capital of Kuala Lumpur, which held the title of world's tallest between 1998 and 2003.

But he admits his present project not only poses unprecedented construction problems - if only because it is boldly going where no building has gone before - but also offers new perspectives on a puzzle that has confronted builders since before the Tower of Babel came crashing down. Just how high can man build?

"Supertall, slim buildings present quite specific technical problems," says Sparks, who has been working in Dubai alongside two other Australian surveyors, Doug Hayes and Hamish Roberts. "Basically, you want to ensure that while the completed building will still move, it'll go up straight - that in perfect conditions it rests exactly perpendicular."

That becomes a major challenge when, inevitably during construction, the raft foundation settles and tilts, the concrete creeps and shrinks, and the rising tower is moved - by as much as 20 centimetres in 10 seconds - by shifting wind and crane loads.

To make things even more interesting there are no surrounding buildings around on which surveyors can take a fix and the Burj Tower - inspired by the geometry of desert flowers and the patterns of Islamic architecture - is not a simple square, or rectangle.

"It's built in a star-shape," Sparks, 59, says. "That means the number of control points needed for the formwork [temporary moulds which shape the concrete] is multiplied many times over. Instead of four for each floor there are more than 200."

Traditional methods of "plumbing up" using sightlines through openings in the floors have been abandoned in favour of a combined system which is a world first. It uses a tilt-meter, that measures the tower movement, and a global positioning system installed at intervals in the formwork.

"Because we have the latest 'Rolls-Royce' equipment and complex, purpose-built software we can obtain and process results accurate to within five millimetres, even though the top may be shifting, vibrating. It's not been done before." Having spent several months in Dubai, setting up the survey system and supervising initial construction work, Sparks is back in Australia, working out of the Newcastle offices of the engineering consultancy Connell Wagner.

He returns to Dubai early next month to check progress. "We're up to 20 storeys. And, well, so far, so straight." Elsewhere, skyscraper enthusiasts watch and wonder when and where the next tallest building will be erected.

After the terrorist strikes on the 417-metre towers of New York's World Trade Centre, experts such as Ron Klemencic, chairman of the Council on Tall Buildings and Urban Habitat in Seattle, which arbitrates height claims, warned it may be generations before man reached so high again.

Although some mega-projects have been shelved - more because of the Asian financial crisis than fear of attack (see panel) - a check on respected websites such as skyscraperpage.com suggest there is no shortage of contenders for the world's tallest title.

One proposal - the Al Burj - is for a site barely 50 kilometres from Burj Dubai, while another, in the "City of Silk" complex, is in the nearby Gulf state of Kuwait. More likely, the challenge will come from Singapore, Korea or China, where Shanghai boasts the world's fourth-largest building, or Japan, where futuristic plans for a 1000-metre-tall Sky City, with accommodation for 130,000 people, are reportedly being taken seriously.

Even more sci-fi visionary are projects such as the 300-storey "Bionic Tower Vertical City", predicated on world population growth and increasing land shortages, and "Urbis Interminatus", or Boundless City, another mile-high dream.

Clearly, though, more than 120 years after the first skyscraper (commonly held to be the 10-storey Home Insurance Building in Chicago) and exactly half a century after Frank Lloyd Wright designed a mile-high Illinois Tower for the same city, the only way is up. The only question is: how far?

"There are concept buildings around that go to two or three kilometres high, and from the engineering construction point of view they are entirely feasible," says Sparks.

He points to advances in faster-setting concrete mixes, steel skeleton fabrication and movement control of buildings, relying on huge concrete pendulum "dampers" to counteract threats such as abnormally high winds and earthquakes.

As the popular science writer Ron Gluckman explained, "No structural limit is in sight. Modern buildings are basically thin curtains draped on high-stress steel or concrete materials."

Nevertheless, there are limitations. They are logistic: the challenge of moving men and building materials from ground to working level. Cranes and lifts must become more efficient and new ways found to pump cement more than 500 metres, says Sparks.

They are economic. Sparks says most of Burj Dubai will easily be let to prestige tenants, but most supertall buildings are status symbols, expressions of national pride rather than investment acumen. "Suitable only where money is no object."

They are cultural. Lepik enthuses that supertalls give people "the chance no only to enjoy dizzying heights … but to live, to work and to eat together in man-made chains of architectural peaks … they are an endlessly progressing, self-fulfilling utopia".

Mir Ali, the author of Art of the Skyscraper, is more sceptical, famously asking, "Who wants to live in a building one mile high?" Far from liberating, they could be claustrophobic. And low cloud could obscure the view.

Sparks shares Ali's reservations. Working and living at such heights would takes some getting used to, he says. "You go from ground level to, say, 350 metres in a hurry, it's not surprising your heart drops to your boots."

And there may be medical limitations. There have been suggestions recently that the lifts in the Burj Dubai will be slowed, after advice that projected speeds of 18 metres a second (about 65 kmh) could put people with heart problems at risk. They are now expected to travel at about 35kmh.

Meanwhile, Sparks - who last year was honoured by the NSW Institution of Surveyors for his expertise in super high-rise buildings - has his feet firmly on the ground. "Oh, I'm keeping myself busy doing basic survey work for clients like State Rail." Still, he must have struck it rich in Dubai? "Quite the reverse, I'm afraid," he says cheerfully. "The client's view is that there is so much kudos attached to the project that the fee can be reduced accordingly."