slab required reinforcement

[spspro]

Hello, I need help with calculating slab reinforcement.

I am calculating contour supported slab I get a strange required reinforcement

I mean there are a big amount of bottom reinforcement in the corners over supports.

I think it should not be so, because I choose calculation type "simple bending" maybe I do something wrong.

Any advice, please

[Artur.Kosakowski]

Slab works in both directions and  that is based on the results (bending moments) you get from the static analysis of the model.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[spspro]

OK, I understand that, but

1. Moments in the plate corners are smaller than in the midpoint of the

slab, and the amount of reinforcement is bigger in corners.

2. And why the moments diagram shows negative moments in the corners of the slab, should not it be

like in edges, I mean the positive moments.

It is a little bit illogical the negative moments and big amount of reinforcement over supports.

Is there any to avoid it?

[Artur.Kosakowski · Accepted solution]

1. For W&A method you include Mxy which is 0 in the slab's center.

2. That is the numerical effect - you can ignore the results from the very corners of the slab and use the values from the centers of the surface elements at these locations instead.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.