Terry Ruth wrote:This is why I tell people to get soil test before they dig and some jurisdictions require it. A geotech report before digging is even better. Do you have access to a lab to get a plastic index and compression test? You'll want to bring them at least two samples at your floor 120 CM deep at opposite sides of the perimeter.
It sounds like you have a high PI and your grade is not right for proper drainage. Maybe good finding the issues now vs later.
Marc Levesque wrote:hello,
personally,i am a big fan of first evaluations.Sounds like the moisture has made the ground un-moldable.
If time is not a concern,what if you drained excess water by digging a hole in the middle of pit so that it
could collect water,then once side walls dried out you could re-shape the footers?
just my two cents, Marc
Terry Ruth wrote:Not to sound critical or sarcastic but it sounds like your geologist has some questionable design practices, this should not have happened. PI can vary drastically on a site that is why we obtain two samples min @ depth so that we understand the variations. Looking at the general area as a guide is not good practice. Large variations in soil properties can and has caused future settling and buckling issues from high hydrostatic pressures making a compacted footing floor sub-base necessary, such as locking aggregates and/or NHLs, Pozzolans, or OPC soil stabilizers, that take PI down at the sidewalls and improve bearing strength. 105 KG/CM2 min. compression.
Terry Ruth wrote: My guess is your PI and moisture holding capacity is too excessive (IE: PI>30) for a good foundation design that is why under liquid load the soil collapses due to not being able to handle its own weight. So getting a good soils engineer there to properly access the situation would be a first step.
Terry Ruth wrote:Concrete needs to dry at the correct rate and having a heavy rain come along that stagnates around it can cause a complete R&R if the required compression is not reached in time, usually 30 days. Might want to consider a continuous drain tile to daylight, they and the footing floor should have positive drainage and filled with a course wash sand or river rock. Backfill the footer with a loose slightly damp low (PI<16) soil, no large clumps. Fill it uniformly around the perimeter in small courses.
Terry Ruth wrote:Once you redo the trenches properly, you could consider ICFs. Not sure if you can find any 50 CM which sounds excessive, you only need 1 CM curbs past walls. Durisol or Faswall makes an excellent ICF although the shipping may be cost prohibitive.
I think Amvic ICFs are the most commonly used here, and I'm not sure what else is available.
I haven't seen ICFs suitable for a wall thickness that gets close to 50 cm. Okay, 50 may be excessive, you think, but where do I draw the line? What is acceptable instead of 50? If it were 40 instead, do they make ICFs with that specification? NB: 50 is the thickness of the foundation wall, which is not resting on a wider footing.
R Scott wrote:Common problem. Clean up the trench best you can, pour footer at the base of the trench, then use block or forms to make a thinner wall, then backfill. It sucks, but not the end of the world.