Square opening in a solid slab
Square opening in a solid slab
(OP)
I am designing a 25cm (~10") two way solid slab. The dimensions of the slab are 300cm x 300cm (120" x 120"). The slab contains a square opening; 70cm x 70cm (28" x 28"). My question is what design considerations do I need to consider when designing this slab? Do I need to provide beams around the edges of the opening or is it small enough that it can be disregarded?
Thanks!
Thanks!






RE: Square opening in a solid slab
RE: Square opening in a solid slab
Also - What's this cm business!?!
RE: Square opening in a solid slab
I don't know what the spacing is yet. Probably 20 cm or so (~6").
We use the metric system around here :).
RE: Square opening in a solid slab
Converting to proper SI dimensions, you have a 3000 x 3000 slab supported on walls all around. There is a 700 x 700 opening about 300 away from a corner in each direction. So I would model that as a 1000 x 1000 opening, leaving you with an uninterrupted 2000 width in each direction. I would put all the required bottom reinforcement in those two bands, then use the same reinforcement in the interrupted strips. You will have twisting moments in the corners without the hole, so make sure to reinforce those adequately in the top.
RE: Square opening in a solid slab
RE: Square opening in a solid slab
RE: Square opening in a solid slab
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: Square opening in a solid slab
BA
RE: Square opening in a solid slab
RE: Square opening in a solid slab
actually countries that use mks system always use cm, it's kind of funny how the world wants the SI system but it is unnatural to work with [as much as imperial in my opinion], it's not like I buy 10 newtons of chicken in the supermarket, we buy stuff in kilograms. Plus to those familiar with cm, it's just a 10^1 conversion to mm and numbers are smaller to work with.
RE: Square opening in a solid slab
To the contrary, for engineers it is unnatural to work in centimetres, unless you are a dressmaker. Engineers don't worry about chickens. The beauty of SI units is that every thing is in multiples of 10^3. If you ever use it, you will love it. The first 20 years of my career were in the US, the last 20 in Australia. I wouldn't want to work in kips, feet and inches again.
RE: Square opening in a solid slab