Reinforced concrete structural analysis and design

[harry4]

Hi. do houses' strip footings (those that are supported on mass concrete piers) that are supporting brick and timber wall frames require design for torsion or is the earth restraint sufficient?

 

[JedClampett]

1. First of all, a post titled structural is kind of vague.
2. Kind of a run on sentence.
3. Should footings require a torsional analysis? Probably.
4. Is it ever done? No.

 

[AnimusVox]

I believe there's something in the code that says if your center of rigidity (talking about LFRS) and your center of gravity for your building are such and such close together you don't need to worry about torsional effects. If it turns out you need to consider torsional effects I would make some conservative assumptions and evaluate the concrete piers for their lateral capacities.

 

[hokie66]

Agree with Jed.

AnimusVox, the OP is talking about local torsion on the grade beams, not global torsion on the building.

 

[msquared48]

I think the OP is talking about torsion on the strip footing due to an eccentric loading from the brick.

Again, unless this is a lot of brick and a very wide strip footing, usually not.

Mike McCann, PE, SE (WA)