When to consider a beam supporting slab 1

[LMW.dk]

Hey guys. I want to make a simiiar detailiing, however I'm confused about what do do in order to have this consideration right:

My slab shall be supported by the beam so my slab calculation would be right. What to do with the reinforcemenet in order to have such a consideration?

http://files.engineering.com/getfil...8fce-4c32-83cb-8845cedc9da0&file=pile_cap.jpg

 

[JAE]

Can you ask a more specific question? From your attached drawing I see a pile cap with a slab coming into it.
I cannot see a beam in this drawing.

If you are asking about how to reinforce beams, that is a very basic engineering question - perhaps ask your mentor?

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[LMW.dk]

No I'm asking why can you consider the slab supported by the beam?

 

[hokie66]

Possibly it is because English is not your first language, but we don't understand what you are asking. But one thing is apparent...there should not be a joint as shown between the beam and slab. They should be cast monolithically.

 

[KootK]

From a strength perspective alone, your beam can be considered to support the slab so long as it has enough strength to support the load transferred to it by the slab.

Because your beam is no deeper than your slab, however, you may have problems with deflection and crack control. The beam may not be stiff enough to make your slab "feel" supported until well after significant cracking and redistribution has taken place. I'd recommend:

1) a beam at least twice as deep as your slab
2) a beam at least as deep as its span divided by 20.
3) numerical verification that beam deflections are within specified limits

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[hokie66]

KootK,
Are you psychic? With the information the OP has given, how do you know the relative depths of the beam and slab?

 

[LMW.dk]

You can see it on the attached file. lol.

 

[LMW.dk]

Kootk so on your opinion my beem should have this height ( see the attached file). The problem is the reinforcement of this height beam will be problematic because i also need reinforcement in my pilecap etc.

http://files.engineering.com/getfil...a9-46dfacc92b81&file=the_blue_is_the_beam.jpg

 

[KootK]

Finding the beam was a little where's waldo-ish.

I like the new beam depth. Reinforcing interference shouldn't be an issue in my opinion. Make some minor tweaks to the depth and the layering until everything fits.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.