small span RC Zig-Zag beam design

[D.Jaya]

Dear Structural Engineers

For a proposed 4 storied apartment building, as per the Architects requirement a Zig-Zag RC beam to be designed in between 2 columns at the 1st, 2 nd and 3 rd floor levels(Please refer to the attached typical part plan)
The structure was analyzed for loadings using a commercial software and found that maximum design BM at this particular beam is only 31.83 KNm
1.Is there any approximate method to design a RC Zig-zag beam
2.How do we get the Torsional efffects and incorporated in to the design

 

[dik]

Bad idea... maybe better:

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[D.Jaya]

Dear Dik
Thanks for your opinion
Also I will assume that the blue color sections you suggest in your proposal- to be act as corbel members connected to the columns

 

[dik]

No, columns... if you have very little line load from the exterior walls, you could look into using a cantilever slab. The column approach is less prone to problems.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[BAretired]

Why use a zig-zag beam? The span is only 9'-0". Use a flat slab spanning between columns at each floor level and eliminate the beam.

BA

 

[dik]

BART: It depends on the outside wall line load and construction. If small OK... just have to watch out for deflections and creep.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[MSUK90]

As suggested by BAretired, just consider a flat slab spanning between columns and analyse and design accordingly..
Have done this numerous times.
No idea of a rough/accurate analysis of zig-zag beams..
I would consider two cantilever beams supporting the central beam if beams need to be used(the upper cantilever is without a back-span though).

 

[D.Jaya]

Dear BAretired (Structural)and MSUK90 (Structural)
Thanks for your opinions