Wider RC Beams, Small Column

[drago8]

Dear All,

I wish to seek advice and guide on how to tackle this problem.

Currently, we are designing a four storey shop/residential buildings with two level of basements. At one of the floor, as an alternative to post-tensioned beams, we are thinking of doing a wider RC beam (1800x700) while our column is roughly 450x450. (see attached picture)

What check shall I be doing? Using the software, it tells shear in the beam is okay. The beam does not fail. However, I would also like to do manual calculations for this.

What other check shall I carry out? Punching shear?

Thanks for your help!

#LoveWins

 

[KootK]

Punching shear is a good way to go if your code doesn't address this situation directly (mine doesn't). A good detail that will work reliably is to continue your beam stirrups through the column so that you can pull in shear from the portions of the beam to the sides of the column. If shear demand is low, you can also just check one way shear based on the width of the column and leave it at that if it works. I noticed that you've got a column transfer situation in the background so your demand is likely pretty high in some spots.

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.

 

[drago8]

Hi KootK,

I did not encounter that check in my code also. How do you do checking for punching shear in the beam? Mind to illustrate how that detail is?

Yup, there is column transfer also in it. Was thinking to the haunch at the part where the column transfers are.

#LoveWins

 

[KootK]

How do you do checking for punching shear in the beam?

Just like you'd do it for a slab.

Was thinking to the haunch at the part where the column transfers are.

That sounds like expensive formwork. I'd try to make it work it stirrups etc.

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.