Dubai

[Talon]

I am a Golfer..lol... but sometimes you can learn lots of things by watching this sport that many people think is very boring.... but you will be happy to know that I am not planning on talking about golf here and now... though from watching the golf, as i often do, three weeks ago they had what is called the Dubai classic... now if anyone has seen the most recent of the Nike and Tiger Woods adverts the tall building that he hits out into the ocean from is in Dubai.. and it was filmed there just a week or so before the tournament itself... but during the tournament, which btw I watched for four days for approximatly 8/10 hrs per day..lol.. anyway during it the tournament the commentators were giving out all sorts of facts about Dubai.. I found much of what they were saying quite facinating(did you know it takes 16 million tons of water per day to irrigate this golf course..lol) and as luck would have it I found something which I am now gonna bore all you guys with..lol... here it is...


PALM AND THE WORLD ISLANDS
What: The largest man-made offshore islands
Where: dubai, united arab emirates
Cost: $3.5 billion
Crux: Two islands built in the shape of giant palm trees. The "trunks" are 5 miles long, each topped by 17 "fronds" up to 330 feet long. A third island group is shaped like a flat map of the globe. Materials: 4.2 billion cubic feet of dredged sand and 50 million tons of rock.

In 1975 there wasn't a single high-rise in the sleepy fishing village of Dubai. But, flush with oil riches and grand ambitions, the business capital of the United Arab Emirates is now sparing no expense to reinvent itself as a Middle Eastern Oz. Exhibit A: Two islands being built 3 miles offshore in the outline of giant recumbent palm trees. Each 5-mile-long trunk sprouts 17 fronds up to 330 feet long, on which a mind-boggling collection of villas, hotels, marinas and shopping complexes will be built. Everything is to be connected by high-speed monorail.

The first island was completed in late '03 after two years of work. Engineers mapped the island's shape via GPS surveys accurate to 2 centimeters. Seven dredgers, 20 miles out to sea, each filled a 5,200-to-22,000-cubic-yard hopper every hour. The hoppers in turn deposited more than 2 billion cubic feet of sand in the appointed areas. "We had to start before there was any protection from the breakwater," says Mark Lindo, engineering manager for the Dutch marine contracting firm Van Oord ACZ, "so we built it 13 feet below sea level." When 9 million tons of rock in 5-ton chunks finally sheltered the palm, Lindo raised it to its final height of 13 feet above sea level.

Even as Lindo begins Palm Island No. 2, he's about to start an even bigger project, an archipelago of 250 islands, called the World, laid out to mimic Earth's land masses. It will be 5 miles across and require 200 million cubic feet of sand, and 30 million tons of rock. "It's enormous," says Lindo. "In Europe or America it would take 10 years of planning and studies to do something like this. But in Dubai it's the other way around. We just do it as we go."

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Now they are also planning on building this..... to be the largest building in the world..
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BURJ DUBAI
What: The world's tallest building
Where: dubai, united arab emirates
Cost: $1 Billion - $2 billion
Crux: A 2,000-foot-high building capable of withstanding 120-mph winds.

What good are islands in the shape of palm trees and maps of the world if you can't see their outline from high above? Dubai so yearns for tallest-building bragging rights that the Burj Dubai's developers are attempting to thwart any potential competitors by keeping secret its exact height and number of stories (as well as a precise estimate of its price). Suffice it to say, the Burj will be "comfortably higher than anything out there or on the drawing boards," says William F. Baker, a partner at Skidmore, Owings & Merrill and the Burj's lead structural engineer.

Early designs placed the massive residential and hotel tower well above 2,000 feet. At that height, "vortex shedding" -- eddies of wind, like the wake behind a boat -- develops at a building's top stories. As air whips around the tower at speeds reaching 120 mph, low-pressure zones occur on one side, then the other, setting up vibrations, known as resonant frequencies, that can literally shake the structure to death -- which is what happened to Washington State's infamous Tacoma Narrows bridge in 1940, when high winds snapped a cable and sent the third longest suspension bridge in the world crashing into Puget Sound. Older skyscrapers like the Empire State Building are immune because they are built out of heavy steel. But to erect a tower more than twice as high requires a construction with even greater damping qualities. The Burj will be made of poured concrete that contains blast furnace slag and microsilicates -- a material that's almost as strong as cast iron, yet more resistant to damage due to vibrations because the natural cracking in concrete dissipates the energy.

The taller a building is, though, the more it flexes, increasing its likelihood of flexing to its breaking point. Abetted by extensive computer and wind-tunnel testing, SOM designed a building with numerous setbacks and wings to scatter the wind. "The wind sees 18 different sections," says Baker, "each with a different vortex-shedding frequency. If we didn't do that, the building would just fall down sideways."

Keeping the building standing is only the first of a complex series of problems in a tower so high. The Burj's relatively small footprint requires a single 11,000-voltage power line routed through a series of transformers throughout the building; Dubai's burning sunlight necessitates coating the windows with special glazing; water pressure must be enhanced with a series of zoned pumping stations; and, to minimize commuting time, the elevators will zoom at 3,600 feet per minute. Going up, that is. "Coming down has to be a lot slower," says Raymond J. Clark, SOM's partner in charge of mechanical and electrical engineering, "or else you'd blow out people's ears."

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I find this all quite fascinating.. especially due to its geographical location and with the way things are politically in the world today.... but it does look like Dubai.. wants to be the tourist destination of tomorrow..

so we had all better start saving

[kathyv]

Wow! Very cool!

Building these islands is fascinating! Engineers learned a lot when they built the Hong Kong Airport and had to create an entire island to put it on.

Hopefully, erecting the worlds tallest building won't be an invitation to various groups of crazies who see it as a target.

Is that an area prone to earth quakes? If so, it would be interesting to know the technology used to protect it from tumbeling.

I'd go there! Wonder if women will be allowed to go up and look down?

[Talon]

Yes I hope that it wont become a target either... i think they are either very brave or very stupid to be trying to build such a tall building with the political situation the way it is...

Earthquakes..I am not sure of... I was wondering though about the wind...what happens if the wind is higher than 120mph..lol

lol@women looking

[Mistress]

[i]Kool Info Talon.. I didnt actually even know where Dubai was .. lol.. until you enlightened me.. lol.. urggg.. hee hee

I have found a wee bit of information on the building of the World Trade Center.. (in fact there is much on the web) lol... however, I'm posting it with hopes that it helps a bit with the "Wind" question that you had about large towers I hope it helps a bit.. if not.. then there is more out there on the web about this issue

World Trade Center

Location: New York, New York, USA
Completion Date: 1972 (Tower One), 1973 (Tower Two)
Cost: $400 million
Height: 1,368 feet (Tower One), 1,362 feet (Tower Two)
Stories: 110
Materials: Steel
Facing Materials: Aluminum, steel
Engineer(s): Skilling, Helle, Christiansen & Robertson

Constructed by the Port Authority of New York and New Jersey in the early 1970s, the World Trade Center towers were, for their time, the best known examples of tube buildings. Tube buildings are strengthened by closely spaced columns and beams in the outer walls. The closely spaced columns and beams in each tower form a steel tube that, together with an internal core, withstand the tremendous wind loads that affect buildings this tall.

Aside from withstanding enormous wind loads, the World Trade Center towers were also constructed to withstand settlement loads. Because the towers were built on six acres of landfill, the foundation of each tower had to extend more than 70 feet below ground level to rest on solid bedrock.

The two towers were unable to survive the effects of a direct hit by two hijacked commercial jetliners during terrorist attacks on the morning of September 11, 2001. Although they were in fact designed to withstand being struck by an airplane, the resultant fires weakened the infrastructure of the building, collapsing the upper floors and creating too much load for the lower floors to bear. Shortly after the attack, both towers collapsed.

At the time of their completion in 1973, the World Trade Center towers were the two tallest buildings in the world. Two years later, the Sears Tower in Chicago seized the coveted title.

Here's how this skyscraper stacked up against the biggest skyscrapers in the world.
(height, in feet)
World Trade Center
1,368' (Tower One)
1,362' (Tower Two)

Another Different artical
World Trade Center Commentary

"Yamasaki's commission to design the World Trade Center with the New York firm of Emery Roth and Sons...house(s) anyone and anything connected world trade. The program presented to Yamasaki, who was selected over a dozen other American architects, was quite explicit: twelve million square feet of floor area on a sixteen acre site, which also had to accommodate new facilities for the Hudson tubes and subway connections—all with a budget of under $500 million. The vast space needs and limited site immediately implied a high-rise development that...make(s) the adjacent drama of Manhattan's business tip seem timid in comparison....

"After studying more than one hundred schemes in model form, Yamasaki decided on a two-tower development to contain the nine million square feet of office space. One tower became unreasonable in size and unwieldy structurally, yet several towers became too approximate for their size and 'looked too much like a housing project'; whereas two towers gave a reasonable office area on each floor, took advantage of the magnificent views, and allowed a manageable structural system. The twin towers, with 110 floors rising 1,353 feet, ... (are) the tallest in the world. From observation decks at the top of the towers it...(is) possible to see 45 miles in every direction....One distinct advantage of the project's enormity is the architectural opportunity to advance the art of building. Yamasaki re-examined the skyscraper from the first principles, considering no ground so hallowed that it could not be questioned, especially in view of the potential of modern technology. The usual economic prohibition on 'custom-made' was out, as virtually anything made for the Center would automatically become a stock item. 'Economy is not in the sparseness of materials that we use,' said Yamasaki of his $350 million estimated cost, 'but in the advancement of technology, which is the real challenge.'

"The structural system, deriving from the I.B.M. Building in Seattle, is impressively simple. The 208-foot wide facade is, in effect, a prefabricated steel lattice, with columns on 39-inch centers acting as wind bracing to resist all overturning forces; the central core takes only the gravity loads of the building. A very light, economical structure results by keeping the wind bracing in the most efficient place, the outside surface of the building, thus not transferring the forces through the floor membrane to the core, as in most curtain-wall structures. Office spaces will have no interior columns. In the upper floors there is as much as 40,000 square feet of office space per floor. The floor construction is of prefabricated trussed steel, only 33 inches in depth, that spans the full 60 feet to the core, and also acts as a diaphragm to stiffen the outside wall against lateral buckling forces from wind-load pressures.

"The other primary obstacle to be overcome in the skyscraper is the elevator system, and Yamasaki has shown himself equally imaginative here. A combination of express and local elevator banks, called a skylobby system, it is particularly efficient because it requires fewer elevator shafts—thus freeing approximately 75 percent of the total floor area for occupancy; had a conventional elevator arrangement been adopted, only approximately 50 percent would have been available. The building has three vertical zones; express elevators serve skylobbies at the forty-first and seventy-fourth floors; from these, and from the plaza level, four banks of local elevators carry passengers to each of the three zones.

"From the outset, Yamasaki believed that there should be an open plaza from which one could appreciate the scale of the towers upon approach. There is little or no sense of scale, for instance, standing at the base of the Empire State Building. Yamasaki's plaza...(is) sheltered from the river winds and contained by five-story buildings which...house shops, exhibition pavilions and a 250-room hotel."

"'The World Trade Center should,' Yamasaki said, 'because of its importance, become a living representation of man's belief in humanity, his need for individual dignity, his belief in the cooperation of men, and through this cooperation his ability to find greatness.' "

[Artoo]

Designing for wind load and/or earthquakes isn't a great problem - it just takes money. For earthquakes you put the building on rollers and dampers that move its natural frequencies well away from the earthquake frequencies. Japan and California have the money to do this. Turkey, the next likely site for the earthquake storm that seems to be advancing through the Mediterranean, doesn't. So we can expect a lots of lives lost there. The question is - when? One year or five? You can't cry wolf too often.

Dubai wasn't, AFAIK, on the Med plate boundary but see:
http://www.earth.northwestern.edu/pe...ntro/pbmap.htm

The Anatolian fault looks helluva close to Dubai. However, they have the money to design these problems out - though I'm not sure if I want to go up a tall building there if an earthquake hits. I get scared on a double-decker bus!

Terrorist threat is another matter. I don't for a minute believe that those who attacked the WTC had any idea they would bring down the buildings - even the architects had no idea that could happen. There isn't an engineering defence here. You have to rely on police and intelligence work to prevent an attack on such a scale.

[Mistress]

Originally posted by Artoo
Terrorist threat is another matter. I don't for a minute believe that those who attacked the WTC had any idea they would bring down the buildings - even the architects had no idea that could happen. There isn't an engineering defence here. You have to rely on police and intelligence work to prevent an attack on such a scale. [/b]

[i]Thanks for all that Artoo...

Just one thing..

The problem with the construction of SkyScrapers and the Technology that they use for the wind, earthquakes, etc.. back in the earlier years.. is that the Team of people making the decisions.. forget to consider that "Technology" was going to advance in ALL aspects of life.. and not get stuck in the year of the initial design of these buildings..

The World Trade Center was planned and built, at the time, to be the Tallest Building in the World.. and they did consider the towers getting hit by a Plane.. In fact, I bet they even bet that it would happen, because back in 1945 an Army Bomber crashed into the side of the Empire State building.

Unfortunatelly, what I think they didn't consider was the "Technology" behind building AirCraft... The WTC Towers were only built to withstand a hit by a plane no bigger then a 727 ...! Now wasn't that just silly? What kind of Technology was Yamasaki considering what that? To be clear here, it is not actually the size of the plane persay, more then how much Jet fuel the larger planes can carry. The buildings were also built to withstand heat up to 1500 degrees, but of course that would not be by a small abount of Jet Fuel, and certainly not as much fuel as a 767 can and does carry.

And as far as the Terrorist are concerned.. they knew very well what they were doing and accomplished it. I was also there in the "1993 boming.. and they failed then, because obviously it would take alot more then blowing up a few support beams to take the towers down. But they didn't fail a second time because the Terrorist knew to highjack a large plane.. Aye they knew very well.... did their homework..

Aye... Technology was certainly not on the minds of any of the Architect team and "Yamasaki" himself the day the construction of the WTC went into affect.

[Artoo]

Originally posted by Mistress
Aye... Technology was certainly not on the minds of any of the Architect team and "Yamasaki" himself the day the construction of the WTC went into affect.
[/b]

Fully agree! It's a recurring feature in the history of technology that we keep pushing the boundaries until something drastic goes wrong (not just as a result of deliberatre attack). Then we step back and think a bit. Foretelling the future is a notoriously unreliable game.