Torsion resistance of concrete shearwall core

[Poul75]

Dear structural engineers,

What is your way to design the torsion resistance of concrete section (L, C, T and shaft elevetor)?

Thanks

 

[dik]

For anything bigger than about half a dozen stories, I try to avoid using L, C and T sections... and for these shorter buildings I just take them as the shear flow about the centre. Can you take the torsional elements to the outer walls in some manner?

Dik

 

[ajose]

The torsion design have three or more steps.

Step one is design for bending flexure.
Step two is design for shear force.
Step three is design longitudinal bars for torsion.
Step four is design for shear torsion.
(This process is clear on codes)

For main member for more than 6 stories on seismic areas just follow Dik advise for non seismic areas you can go up to eight may be 10 stories, for auxiliary members well you have to go and design.

Nevertheless when you follow the design process and the beam is over reinforced you must stop and think it over.

 

[hokie66]

ajose,
You have misunderstood the question. The OP asked about design of shear cores which are eccentric, and your answer is for design of individual beam elements.

Poul75,
Big topic. After you study it and have some specific queries, come back with them.

 

[msquared48]

The presence of, or lack of a concrete slab makes a whale of a difference in the analysis method.

Mike McCann
MMC Engineering

 

[abusementpark]

For anything bigger than about half a dozen stories, I try to avoid using L, C and T sections...

Why is that?

 

[abusementpark]

I've never found a good reference for the design of reinforced concrete shear boxes/cores. I'm particularly interested in how people used to analyze these things by hand and how they accounted for the force transfer around openings.

If anybody ever comes across anything, please post it.

 

[dik]

These shapes are problematic and difficult to reinforce if necessary. I prefer symmetcic sections if possible for anything that is starting to get tall.

'Coupled' shear walls and symmetric cores are the easiest... for flexure, shear and torsional shear...

Dik