to be

at the Very top of a skyscraper, this is a bit like flying. Easy to learn in the 96. Floor of the house number 875 North Michigan Avenue, the third tallest building in the United States. “Signature Room” is the name of the Restaurant on the top. It offers spectacular views of the Loop: the City of Chicago within the high-Bahn-ring, with its many skyscrapers including the Willis (formerly Sears) Tower, the second tallest building in the United States.

When you walk through the Restaurant to the tables, which are strung over the entire longitudinal side of the building, you can feel the movement. The soil varies. As in a calm flying plane. It was the sharp Wind from lake Michigan, the encounters, the gigantic building facade and in the upper of a hundred floors, a light is calling Back and Forth. But that is what makes soon-to-be 50-year-old house.

The construction is designed to be able to such movements to intercept. The structural engineer of the renowned architectural firm Skidmore, Owing &Merrill (SOM) designed the Tower to be one of the most innovative structures in the history of the skyscraper: The visible in the facade to the underlying cross-pieces of the steel skeleton to give the building the necessary stability. You remind a little of a half-timbered house.

Jeddah Tower is set to break the record

built in the unusual construction without intermediate supports between the outer frame and core of the building – the first as the diagonally braced tube building. The tower tapers towards the top. As a result, the floor area shrinks to 60 percent. A desired effect, because on the top floors Apartments. And, in the case where the supply of days is light on the smaller Bullet is better. In addition, the sensitivity to Wind is reduced.

457 meters is the “John Hancock Center” is built, and also affectionately called “Hankie” referred to as big as a house, including the antennas. Until the beginning of this year, it got its new name. The Willis Tower, which was five years later, even 527 meters.

Today, houses are built, the are yet again three hundred metres higher. Current world record holder is the Burj Khalifa in Dubai with 828 meters. And in two years, the Jeddah Tower in Jeddah, saudi Arabia, to be finished.

He will be the first house is higher than a kilometre. Possible technical developments, which has brought together the architect and Blogger John Hill, in his book, “Skyscraper”. Some of these developments appear to be even today absolutely amazing. Others, however, is rather banal.

the development of the Elevator made the building of real houses is also useful. Because of high buildings, there was centuries ago. Each tower was higher than the surrounding residential buildings. But to live at such heights – and no one would come, simply because of the poor accessibility of the upper floors. But Church towers rose into the sky.

The 157,38 meters high, in the year 1248, begun in Cologne Cathedral, was long the tallest building in the world. Architects and builders it was not possible simply to crack the 200-Meter mark. It was a static Problem. The higher a building is, the more weight weighed on the walls. From a certain height, even the hardest rock crumbled down stones just under the load. Even more decisive than the development of the Elevator, the invention of the steel skeleton construction, which gave birth to the exterior walls of their load-bearing task was, therefore, writes Hill.

In may 1888, architect Leroy S. Buffington from Minneapolis received the US Patent for a design with steel construction: the structure of a building, completely made of steel girders erected in the floors, Ceilings and walls then have to be inserted.

The Home Insurance Building of 1885 was the first building in the United the new technical achievements, and was, with its ten floors the first skyscraper in the world. It is also the first “modern” high-rise building, which was demolished in 1931 to make way for a new, higher place.

In the year the technology was Mature already, the 381-metre high Empire State Building could be built within a year. It broke the world record for the already finished in 1930, the nearby Chrysler Building. Until the opening of the World Trade center in 1973, the Empire State Building remained the tallest building in the world.

But the twin towers, the terrible end on 11. September 2001 found, maintained their record of only one year, because in 1974, the higher of the Willis Tower was opened. The had to give up the title in 1997, the Petronas Towers (452 meters) in the Malaysian capital of Kuala Lumpur.

But even today, the technology of 1931: cranes will be mounted on the already constructed floors, and lifting the building material from the ground to the top. is similar to As soon as a number of other floors is built to be taken apart, the cranes, in Parts to the top is hoisted up and put back together again.

Simple solutions are usually facilitated with the best

The use of computers and speeds up the development of the skyscraper. And the invention of modern building materials – such as high-strength concrete, super glass, heavy-duty steels, and the use of the latest technology allow us to push the limit further and further to the top.

The architects of SOM have built a whole series of “Supertall Towers” (over 300 meters), which shape the Skylines of metropolises. Since 1936, there is the Chicago-based company. The Burj Khalifa, 875 North Michigan Avenue, the Willis Tower, One World Trade Center (541 meters) in New York, the Busan Lotte Tower in Korea (510 meters) and a number of other country brands in China and the Middle East are of SOM.

A highly complex, technically challenging buildings always start with architects and engineers and a structural concept, says the civil engineer, William Baker, a Partner at SOM for the statics of the Burj Khalifa responsible. Baker’s recommendation to the planners: “Describes your System in words. If you need too many words, is your System might be too complicated.“ Simple solutions are usually the best.

as the basic construction of the Chicago Willis Towers. The SOM-specialists Bruce Graham and Fazlur Khan were commissioned with the development. The two came in, since Graham gave his colleagues a bunch of cigarettes in front of the nose, some of which towered above the others, and asked him whether the work could. The inspired Khan to the development of the first bundled tube structure.

From the cigarette box to the Burj Khalifa

Well, the lights in the skyscrapers are rectangular, but somehow, the 108-storey Willis Tower is reminiscent of a packet of cigarettes, some Cigarette sticking out in different lengths. The nine tubes are held at four Points by encircling truss belt, each two floors high.

To get in to the office no restrictions by diagonal struts, are housed in these floors, engineering floors. In the case of Hankie, the Diagonals have not disturbed yet.

The cigarette packet seems to have the Burj Khalifa, the firing incident is delivered. With its completion in the year 2010, a new era had begun, writes John Hill: the “Megatall Towers” of more than 600 meters in height.

The process in which the SOM architect Adrian Smith and structural engineer Baker from its original design of a 520-Meter-high building, adopted, began in the wind tunnel. He cut too bad. The new design allowed for a higher structure. How high, exactly, was kept until shortly before the completion of a secret. You want to prevent that competitors would exceed the height.

Baker and Smith used a novel method based on a Y-shaped plan, with three of the building columns is based. The pillars support each other, as in the case of a tripod, you will be guided in the Central axis.

the Wind Blows against one of the Supports, the underlying unencumbered, and thereby stabilizes the high-rise. By this construction, the building was not only wind-resistant and lightweight, even more light was able to be in the skyscraper.

The Burj Khalifa, which stands on a 6.7-metre-thick concrete Foundation slab based on 194 concrete from 1.5 metres thick and with a depth of 43 meters is stored. The Foundation was completed in 2005. And two years later it was 100. Floor reached about half.

“This speed was possible because the executing construction companies, Samsung began at least two innovations,” writes Hill, “a self-climbing formwork and high modern pumps, with which the concrete is in previously unheard-of heights of pumps”. And here, too, Innovation was necessary: – cooled concrete pipes. Because more than 50 degrees the outside temperature of the liquid concrete would have been hard, even before he had quite arrived at the top.