Tall Buildings example essay topic
Older buildings, like the Empire State Building, were built so that their core withstood all bending stresses. But structural engineers have since found that by shifting the bracing and support to the perimeter of a building, it can better resist high winds. The most advanced buildings are constructed like hollow tube, with thin, outer columns spaced tightly together and welded to broad horizontal beams. Toronto's First Canadian Place and New York's World Trade Center towers are all giant, framed tubes. A super skyscraper would undoubtedly need extra rigidity, which you could add by bracing its framework with giant diagonal beams.
You " ll see this at Chicago's John Hancock Center where the architect has incorporated diagonal braces right into the look of the building, exposing five huge X's on each side to public view. Alternatively, you might design your building like a broadcasting tower, and tie it to the ground with heavy, sloping guy wires extending from the four corners of the roof to the ground. A control mechanism at the end of each cable would act like a fishing reel, drawing in the cable whenever the sway of the building caused it to slacken. Tall buildings also encounter the problem of vortex shedding, a phenomenon that occurs as the wind swirls around the front corners of the building, forming a series of eddies or vertices. At certain wind speeds, these vertices vibrate the building, threatening to shake it apart. In New York City's Citicorp Center, engineers have tackled vortex shedding with a 400-tonne concrete block that slides around in a special room on one of the upper stories.
Connected to a large spring and a shock absorber, and riding on a thin slick of oil, the big block responds to oscillations of the building by moving in the opposite direction. Other ways to disrupt vortex shedding include making several large portals in the upper part of the tower, through which the wind passes freely. In New York City's World Trade Center, vibrations are dampened with special sponge like pads sandwiched in its structure. The price tag on a super skyscraper is going to be enormous, but one way to.