PT slab on grade for slope creep

[drt]

Does anybody know if PT slab grade foundations are used to help mitigate the effects of slope creep ? Slope creep is a phenomena which occurs on slopes constructed of expansive soils. After several years of wetting and drying cycles the slope begins to creep downhill. Slope creep eventually leads to a loss of the lateral and vertical support.

I've seen others recommend PT slabs to help mitigate against differential settlement (due different fill thicknesses below a foundation).

Seems like both conditions produce differential settlement, and therefore a PT slab would be effective to help reduce the effects of slope creep. Any thoughts ?

Thanks

 

[ishvaaag]

Prestressed or not, a slab extending beyound the building will cause the water content be more stable. If you combine this with diverting any surface waters coming from up the hill, you will have enhanced the suppor of your house locally, since less able to undergo the whole weather cycle on water contents of the soil. Being prestressed it is assumed impermeability will be bigger, so it is good.

This scheme will be defeated any time any permeable layer is embedded that furnishes waters to the unstable clays, but should work where the clayey nature is general. You may include cutoffs embedded in the soil, but then I suggest make them able to undergo structural action, and with your building firmly anchored to the soil, for otherwise you may be pre-cutting the piece to slide.