What do you think of this residential concrete wall foundation failure? 1

[CivilSigma]

Had the pleasure of investigating a foundation wall failure of a garage structure:

https://imgur.com/a/9W0z6PM

Home built in 1970, in Ontario, Canada. Foundation susceptible to frost heave if not embedded adequately.

First 5 pictures are of the side foundation wall, it is non-load bearing (supports truss gable end and self weight).
Last 3 pictures are of the front garage foundation wall, which is load bearing and supports point loads from garage opening headers above.

Apparently, the home owner noticed a hairline crack on the side wall paring, retained contractors for repair, and after they dug up the soil, they noticed all these cracks.
The foundation wall has moved in "block form" a couple inches. No distortion to wall stud framing or siding along the exterior.

I don't think it's flexural failure of the wall considering that it's effectively pin-pin boundary condition.
The wall failure is near the ground elevation. If it's flexural failure, I would expect the failure to be at mid span, with distortion of framing above.

Could this be a cold joint, gone bad?

What do you think?! This is the first time I've seen residential foundation failure this bad

 

[bones206]

Not sure what to make of it, but the multiple layers of sill plate in this photo looks pretty weird:

I hope they put some shoring in for that garage door wall. Doesn't look like it has much (or any) bearing on the foundation.

 

[CivilSigma]

Yea it is very unconventional construction. I'm not sure why they would concrete embed sill plates. Maybe trying to fix a mistake with finished elevation height?

 

[Colostruct]

It's hard to tell from your photo. It looks like a shallow unreinforced footing that was cast against soil? There could be a host of reasons for the settling including soft soils, poor drainage, utility drain excavation or structure built on loosely placed fill to level up prior to construction. It's also possible that the concrete was just a really low strength or was placed improperly. Around here we have alkali soils that eat older concrete especially when the aggregate is reactive too.

To do an engineered repair, unless you know the soils well, I would get a geotechnical engineer to take a look.

 

[bones206]

Based on the photo of the sill plates stacked BELOW the top of foundation wall, and the fact that you don't see much distortion in the wood walls, I would suspect a construction defect that was covered up cosmetically by the builder. The original defect may have been an unintentional cold joint from delay between concrete trucks, or placing concrete part way up the forms then coming back around to finish it off with another placement after the wall had already begun to set and could not be consolidated properly with the new concrete.

 

[Craig_H]

I agree with the others that this is likely some sort of construction defect that got covered up and is now rearing its ugly head. It looks like one end of the failure involves several sill plates and other wood bits cast into the concrete, which likely created a failure plane to get things started. The question in my mind is: what pushed the wall and caused it to shift? Did the interior garage floor settle, did the ground beneath the garage floor freeze or heave? Whatever caused the force to push that wall out will also need to be mitigated to prevent further damage in the future.

 

[CivilSigma]

I'm thinking maybe surcharge from the parked cars would have caused, over time, the displacement of the wall.
It's also possible that machinery surcharge during the excavation work would have aggravated the displacement.
If the failure plane has been there for a long time due to construction defect, then it's possible that frost adhesion/soil heave could have slowly pushed out the wall.

 

[bones206]

If it was construction damage, the most likely culprit would be some mishap during backfill/grading. Just based on the timing of sill plate installation.

 

[BAretired]

It looks like the quality of concrete and workmanship was deplorable. The builder probably had no idea how to construct a proper foundation. When the quality of work is this poor, it seems a little pointless to try and determine precisely what caused it to end up such a mess.

BA