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An American article that refers to Toronto's "CNN Tower". The article is from the respectible construction.com website, of all places!
Link to article
West Tower at 610 m would be taller than CNN spire in Toronto.
(Photo by Information Based Architecture)
Buildings
China Building TV Tower to the Sky
(enr.construction.com - 02/14/06)
By Peter Reina
One of China's oldest cities, Guangzhou, is reaching high by starting two record-breaking buildings, both supported by external structural steel skeletons. On one side of the city, foundation work recently began on a 610-meter-tall TV and observation tower, to be the world's loftiest. Across town, foundations for China's tallest building, at 432-m, are also under excavation.
Intended to be the Eiffel Tower of Guangdong's provincial capital for the 2010 Asian Games, the TV structure would be nearly 57 m taller than Toronto's CNN Tower, the current record holder. Sited by the Pearl River, in Tianhe district, the see-through structure will have a 160-m-tall antenna rising from the top-level open observation garden set 450-m above ground.
Also timed for the Asia Games, the 432-m West Tower would dominate Guangzhou Zhujiang New Town. It would be 11 m taller than China's tallest building, Shanghai's Jin Mao tower. The mixed-use building would be enclosed by a vast steel grid stiffening the structure against typhoons. Both towers are products of international design competitions in 2004, won by European teams.
For its winning TV tower submission, the small Dutch firm Information Based Architecture (IBA), Amsterdam, was looking for structure "where all views towards the tower would be different from whatever vantage point," explains director Mark Hemel.
A key engineering contribution by competition collaborator Arup Group's Amsterdam office was to rationalize the structure, says local director Joop Paul. The originall concept was "very random" and with about 1,700 different joints, he adds. The Guangzhou Design Institute also forms part of the design team.
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Design for the TV tower structure takes the form of a tapering oval cylinder, which is twisted to develop a waist of roughly 21.7x27.5 m. The footprint is 60x80 m at ground level, reducing to 40.5x54 m at the top.
Concrete-filled columns, which remain straight, along with the hoop and diagonal steelwork all would spiral up the building forming a exoskeleton. Columns are up to 2 m-dia and made of steel as much as 5 cm thick. Diagonal and hoop diameters are 70-85 cm and of 2.5-4 cm thick steel.
Internally, the concrete core is mainly for vertical access, though it contributes 20-30% of the stiffness at the waist, says Paul. The core also helps support a rising sequence of independently enclosed spaces providing around 100,000 sq m of restaurants, conference rooms and other facilities.
Work on the two-level basement, founded on rock, began late last year. Bids for the superstructure contracts, for 30,000-40,000 tonnes of structural steel, are set to be called this March or April, says Paul. Erection will likely start this year in time for the tower's planned completion in 2009. That's also when the other tall building is due to open.
For the West Tower, the international team of Wilkinson Eyre Architects Ltd. (WEA), London, with Arup's Hong Kong office is handling conceptual design only. With construction already started on the four-floor basement, the South China Design Institute is due to take over detailed engineering this April, says WEA director Chris Wilkinson.
With its podium, the West Tower development would provide 439,000 sq m of space, including 163,000 sq m of offices in the lower 65 floors, apartments and a 370-room hotel at the top.
Its base footprint is triangular with gently curved sides about 60 m long. With its slightly bowed profile, the building side lengths rise to 65 m a third of the way up, reducing to 44 m at the top. "It's not an extrusion," says Wilkinson.
The tower's primary structure is designed as a perimeter diamond grid of concrete-filled tubes, up to 1.6 m dia. Typical levels will have 12 tubes a side, reducing to six at nodes every 12 floors though the numbers may change. "It's an efficient structure" but not the most economical, says Arup's Hong Kong-based director Craig Gibbons. "It also has some esthetic merit."
Over several floors at around levels 70, core walls change into a moment frame, retaining stiffness while creating an atrium though the upper 36 floors. The designers aim to maximize thermal efficiency of the tower by proposing twin-walled, internally ventilated and shaded glass fa'ades, says Wilkinson. Shell and core construction, estimated at about $720 million, may start this year.
Link to article
West Tower at 610 m would be taller than CNN spire in Toronto.
(Photo by Information Based Architecture)
Buildings
China Building TV Tower to the Sky
(enr.construction.com - 02/14/06)
By Peter Reina
One of China's oldest cities, Guangzhou, is reaching high by starting two record-breaking buildings, both supported by external structural steel skeletons. On one side of the city, foundation work recently began on a 610-meter-tall TV and observation tower, to be the world's loftiest. Across town, foundations for China's tallest building, at 432-m, are also under excavation.
Intended to be the Eiffel Tower of Guangdong's provincial capital for the 2010 Asian Games, the TV structure would be nearly 57 m taller than Toronto's CNN Tower, the current record holder. Sited by the Pearl River, in Tianhe district, the see-through structure will have a 160-m-tall antenna rising from the top-level open observation garden set 450-m above ground.
Also timed for the Asia Games, the 432-m West Tower would dominate Guangzhou Zhujiang New Town. It would be 11 m taller than China's tallest building, Shanghai's Jin Mao tower. The mixed-use building would be enclosed by a vast steel grid stiffening the structure against typhoons. Both towers are products of international design competitions in 2004, won by European teams.
For its winning TV tower submission, the small Dutch firm Information Based Architecture (IBA), Amsterdam, was looking for structure "where all views towards the tower would be different from whatever vantage point," explains director Mark Hemel.
A key engineering contribution by competition collaborator Arup Group's Amsterdam office was to rationalize the structure, says local director Joop Paul. The originall concept was "very random" and with about 1,700 different joints, he adds. The Guangzhou Design Institute also forms part of the design team.
advertisement
Design for the TV tower structure takes the form of a tapering oval cylinder, which is twisted to develop a waist of roughly 21.7x27.5 m. The footprint is 60x80 m at ground level, reducing to 40.5x54 m at the top.
Concrete-filled columns, which remain straight, along with the hoop and diagonal steelwork all would spiral up the building forming a exoskeleton. Columns are up to 2 m-dia and made of steel as much as 5 cm thick. Diagonal and hoop diameters are 70-85 cm and of 2.5-4 cm thick steel.
Internally, the concrete core is mainly for vertical access, though it contributes 20-30% of the stiffness at the waist, says Paul. The core also helps support a rising sequence of independently enclosed spaces providing around 100,000 sq m of restaurants, conference rooms and other facilities.
Work on the two-level basement, founded on rock, began late last year. Bids for the superstructure contracts, for 30,000-40,000 tonnes of structural steel, are set to be called this March or April, says Paul. Erection will likely start this year in time for the tower's planned completion in 2009. That's also when the other tall building is due to open.
For the West Tower, the international team of Wilkinson Eyre Architects Ltd. (WEA), London, with Arup's Hong Kong office is handling conceptual design only. With construction already started on the four-floor basement, the South China Design Institute is due to take over detailed engineering this April, says WEA director Chris Wilkinson.
With its podium, the West Tower development would provide 439,000 sq m of space, including 163,000 sq m of offices in the lower 65 floors, apartments and a 370-room hotel at the top.
Its base footprint is triangular with gently curved sides about 60 m long. With its slightly bowed profile, the building side lengths rise to 65 m a third of the way up, reducing to 44 m at the top. "It's not an extrusion," says Wilkinson.
The tower's primary structure is designed as a perimeter diamond grid of concrete-filled tubes, up to 1.6 m dia. Typical levels will have 12 tubes a side, reducing to six at nodes every 12 floors though the numbers may change. "It's an efficient structure" but not the most economical, says Arup's Hong Kong-based director Craig Gibbons. "It also has some esthetic merit."
Over several floors at around levels 70, core walls change into a moment frame, retaining stiffness while creating an atrium though the upper 36 floors. The designers aim to maximize thermal efficiency of the tower by proposing twin-walled, internally ventilated and shaded glass fa'ades, says Wilkinson. Shell and core construction, estimated at about $720 million, may start this year.
