In expanding large cities where ground space is at a premium the only real option is to build up and with the need to cater to the requirements of ever expanding populations buildings are getting taller and taller. Tall buildings, particularly those in already built-up areas present a whole new range of difficulties for the designer, with the most prominent considerations being wind and seismicity. Seismicity today is fairly well understood; potentially active areas are known and identified enabling the designer to anticipate the effects of all but a major disaster. In such cases, there is little to be done but make sure you’re as far away as possible from falling debris.

Wind however is not quite as predictable, especially as mentioned, in already built-up areas, other structures, or topographical features in the proximity of the intended structure can have a significant effect on the speed, direction, intensity, and turbulence of wind, to a point where it becomes the dominant consideration for the designer.

Fortunately, for those of us who live or work in such structures modern analytical techniques which include computer analysis and simulation, together with wind tunnel simulations enable the designer to accurately predict the effects of wind under almost any conditions. To counteract these extreme load conditions affecting high-rise structures, stabilization becomes the dominant consideration.

Horizontal stabilization in almost every case is achieved by means of concrete floor diaphragms, while vertical stabilization is achieved by one of the 4 common options already mentioned:

  1. Vertical Braced Frames
  2. Vertical Rigid Frames
  3. Vertical Shear Wall Frames
  4. Vertical leaned frames

It may seem surprising when you look at some of the seemingly outrageous configurations that modern high-rise structures adopt, but closer examination will show this to be the case. The main difference between a simple low-rise structure and its high-rise counterpart is the way in which the vertical stabilizing elements are configured.

There are any number of possible combinations, the selection of which is entirely dependent on the shape, height, function, and external conditions which the structure must resist.

The following links will illustrate in more detail the most widely applied means of stabilizing high-rise structures, they include:

  1. Internal Core Systems
  2. Braced and Framed Tubes

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