Frost heave

What is the intent of this?
It’s best to remove frost susceptible soils.

jhnblgr said:

https://ascelibrary.org/doi/abs/10.1061/IJGNAI.GMENG-7710

What is the intent of this?
It’s best to remove frost susceptible soils.

Click to expand...

The client cannot remove the frost susceptible soils and considering a compressible expanded polystyrene fill forms, so they need the estimated amount of frost heave.

Reason why they can’t remove?
If they are installing insulation follow shallow foundation design for frost protection
Is this heated or unheated space?
What is the function?
Would the compressible foam compress under dead load or is there a foundation load path that spans the area?

Silts are very bad for frost heave... you have to try to eliminate the frost... extruded polystyrene? High strength if necessary.

Estimating with any accuracy is not likely possible. Perhaps can be somewhat, in a controlled environment like the ASCE study linked above.
You didn't mention ground water table level, that's a major factor. And the rate of frost advance is a factor. Even in somewhat consistent soils, the amount of heave can vary from place to place, and by season.

CarlB said:

Estimating with any accuracy is not likely possible. Perhaps can be somewhat, in a controlled environment like the ASCE study linked above.
You didn't mention ground water table level, that's a major factor. And the rate of frost advance is a factor. Even in somewhat consistent soils, the amount of heave can vary from place to place, and by season.

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GW table is at 1.3 m, and frost depth is about 1.5 m. Also, this material is Fill (not native) primarily silt and may contain trace to some roots/organics. I just need an idea of an upper bound or a very conservative estimate based on the hydrometer, moisture content, frost depth, and GW level (as you suggested) without any additional testing. Is this possible? I have tried to find answers but can't really get anything decent to reference.

Thank you

Insulate under slab per ASCE 32 or similar document. Replace fill material with non frost susceptible soils down to GW depth and install geo textile fabric. However is sounds like you really should install piles since bearing capacity is likely very low