Stress distribution through concrete
Stress distribution through concrete
(OP)
Hello all,
I have a doubt about stress distribution angle:
The stresses underneath concentrated forces can in general be assumed to dristribute through concrete under an angle equal to:
- 33,7º
- 45º
- depends
- other
Is there any standar related?
I am designing and the higher is the angle the more economic will be my solution.
Thank you very much
I have a doubt about stress distribution angle:
The stresses underneath concentrated forces can in general be assumed to dristribute through concrete under an angle equal to:
- 33,7º
- 45º
- depends
- other
Is there any standar related?
I am designing and the higher is the angle the more economic will be my solution.
Thank you very much






RE: Stress distribution through concrete
What exactly are you designing? If it's a slab, have you attempted yield line analysis (fan shape for concentrated loads).
RE: Stress distribution through concrete
I am sure it is more complicated than this but it's a start.
I typically use 45 degrees for, say, checking soil bearing pressure under a post bearing through a 8" slab-on-grade.
RE: Stress distribution through concrete
For wall design itself - use 4 x wall thickness for the width of the wall resisting the concentrated load.
For the footing design under the wall - like calvinandhobbes10 - we use a 45 deg. angle spread unless there is a door or window opening that interrupts it...then it gets truncated smaller.
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RE: Stress distribution through concrete
I have attached a scheme.
The bottom concrete must be able to resist compression transmitted through the upper concrete. Of course, it will be easier if the angle is wide, until it gets truncated.
I have checked uses 1V:2H (63 deg), but EC-2 defines 2H:1H (27 deg) which is radically different. (I am not confused with the angle and its complementary)
And it is curious but I have typically used 45 degrees for a long time. But when I tried to authenticate 45 degrees I didn't find anything.
RE: Stress distribution through concrete
RE: Stress distribution through concrete
Thanks
RE: Stress distribution through concrete
If you have the opportunity, I would be inclined to reinforce the upper concrete such that you can assume the load to be spread out over the entire pedestal width. The lower concrete will likely flex and result in the upper pedestal load being delivered closer to the edges of the upper pedestal anyhow.
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.
RE: Stress distribution through concrete
Section 6.7 of EC-2 is equivalent to 10.14 of ACI. But in the first case the angle of transmission is 26.6º, and in the second case the angle of transmission is 63.7º. How is it possible??
RE: Stress distribution through concrete
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.
RE: Stress distribution through concrete
RE: Stress distribution through concrete