How are typical high-rise buildings designed?
The everyday high-rise construction originally appeared on Quora.
by Aaron Mark, B.S. Building Construction, Virginia Tech
Tension and compression diagrammed.
The picture below shows the major structural components (in simple terms) of a high rise. I’m assuming you’re building a high-rise in the New York Metropolitan area, if not, then some of the techniques and materials might be different in your geographical area.
Basic elevation of a high-rise building.
The first part of any high-rise is the deep foundation, compared to a shallow foundation which you’d see in smaller buildings, like your two-story suburban house. The deep foundation for a high-rise, the majority of the time, involves piles or caissons being drilled/ hammered into bedrock, which would be several/ or over a hundred feet below the soil you dig up on any patch of dirt. The picture below shows that the overall goal is to get to the strong load-bearing rock below the weak soil above it.
The weak soil would not be able to support the weight of a high-rise and thus we need to go down to bedrock.
The foundation is what supports the building above it, and it’s always made out of a combination of concrete and steel. Below is a picture of rebar sticking out of concrete filled piles; the foundation slab rebar will be tied in with the protruding pile rebar and poured with concrete to create our cellar floor.
Just showing the principle of work, a high-rise’s foundation would be much larger than this.
The level directly above our foundation, but still below the ground level is called the substructure. The substructure would be the basement of our building, but in construction parlance, we’d just call it the foundation or basement of the building instead. The picture below shows a completed one-story substructure (the walls and foundation slab have been poured) with the exposed steel columns, and girders to the right, which will eventually become part of the superstructure.
This is a steel framed building with reinforced concrete on steel decking.
Everything above ground is called the superstructure; which consists of load-bearing columns and slabs rising up the height of the building. All of the slabs/columns in this part of the building will be filled with concrete and rebar as shown below.
Usually, the worker guiding the concrete pump here would be not be allowed to smoke while working.
Once all the floor slabs and columns are poured, you’ll have the most structurally important part of your high-rise complete. The picture below shows what a high-rise would look like with all of the foundation, floor slabs, and columns elements complete; remember that every part of the building up until now has been installed with reinforced concrete (a combination of cement and rebar), in either compression or tension supporting loads of the entire building down to the foundation below.
The orange netting is so nothing falls off the floors during construction.
Now that the structural part of the high-rise is complete, all of the interior and exterior work begins to make our building suitable as commercial or residential habitable space. All of our electrical, mechanical, plumbing, and HVAC work would be installed, alongside our walls, windows, roofing system, and flooring systems.