Vertical Crack on Foundation Retaining Wall
Vertical Crack on Foundation Retaining Wall
(OP)
I have a poured concrete foundation retaining wall 32 feet long by 10 feet high (the first 4 feet are 12 inches thick and the remaining 6 feet are 8 inches thick) that has developed a vertical hairline crack from top to bottom (less than 1/16 of an inch wide). The crack does not extend to the footing. The wall is fully reinforced with rebar. Since this wall retains part of a hill and is an integral part of the foundation of a house I am building I want to know if this crack is of concern? Should I add a supporting column behind the crack to reinforce the wall?
Any info would be appreciated.
Thanks.
Any info would be appreciated.
Thanks.






RE: Vertical Crack on Foundation Retaining Wall
RE: Vertical Crack on Foundation Retaining Wall
RE: Vertical Crack on Foundation Retaining Wall
1. When concrete was placed what was the slump?
2. How did the cylinder strengths compare with the f'c?
3. Is the size of the crack uniform in thickness through the height of the wall...did it go through thickness of wall..and approximately where is it located along length of wall?
4. At what age did the cracks start appearing
5. And the soil, what type is it?
6. Any possibility of posting pictures here?
RE: Vertical Crack on Foundation Retaining Wall
overloading is not likely unless the wall is tilting or moving laterally away from the soil. hard to say without actually seeing it.
agree with aggman and jmiec, that a qualified licensed structural engineer review the wall for you.
RE: Vertical Crack on Foundation Retaining Wall
The structural engineer I consulted thought it was a temperature shrinkage crack. I just wanted to get other opinions before deciding whether to reinforce it by putting another wall behind it.
Thanks.
RE: Vertical Crack on Foundation Retaining Wall
RE: Vertical Crack on Foundation Retaining Wall
RE: Vertical Crack on Foundation Retaining Wall
Pray like everything depends on God
Work like everything depends on you.
RE: Vertical Crack on Foundation Retaining Wall
L=32'
Acceptable deflection = L / 240 = 1.6 inches
:::So, the wall at midspan will deflect inwards 1.6 inches, with a crack that would probably be fairly small at midspan. Now, think of the wall in the vertical direction. It will have deflected at midspan 1.6". There would be a much bigger horizontal crack at midspan of the "vertical" wall, than there would be at midspan of the "horizontal" wall. You can also think of it in the stress/strain relationship and realize that the only reason the wall is supported in the horizontal direction is because it most likely failed in the vertical direction. The logical explanation is that it is a temperature crack due to not having control joints in 32' of wall.
CEGG, I don't have a lot of experience in investigations like this, and would like to hear how this crack could be a structural crack.
I'm also curious as to where you are getting that the wall would require a buttress wall at mid span. I've never seen a reference for this, but would love to see it. Thanks.
RE: Vertical Crack on Foundation Retaining Wall
When performing field evaluations alongside structural engineers in the past, a document I used to refer to was ACI 224. It may not be the state of the art but can help elucidate what went wrong in this type of situation.
This NRCMA piece on concrete cracks in basement walls lists ACI 224 as a reference. http://www.nrmca.org/aboutconcrete/cips/07p.pdf