Frost propagation
Frost propagation
(OP)
All,
Looking to increase my knowledge of frost action, especially in terms of how frost behaves and propagates horizontally. It seems as though the growth of ice lenses is usually explained as behaving predominantly vertically through capillary action in frost susceptible soils, resulting in vertical heaving and whatnot. Does anybody have any experience with sidewalls of cuts or sidewalls of soils behind retaining structures having troublesome frost action? Do ice lens and frost propogation occur predominantly vertically rather than horizontally? Thanks for any insight or case studies you can pass along. Happy New Year to all.
Looking to increase my knowledge of frost action, especially in terms of how frost behaves and propagates horizontally. It seems as though the growth of ice lenses is usually explained as behaving predominantly vertically through capillary action in frost susceptible soils, resulting in vertical heaving and whatnot. Does anybody have any experience with sidewalls of cuts or sidewalls of soils behind retaining structures having troublesome frost action? Do ice lens and frost propogation occur predominantly vertically rather than horizontally? Thanks for any insight or case studies you can pass along. Happy New Year to all.





RE: Frost propagation
Jim Houlette PE
Web: www.evstudio.us
Online Magazine: www.evstudio.info
RE: Frost propagation
I have seen many a house basement wall shoved in by frost.
While the subject of capillary action is used by some to explain frost heaving, it more likely is due to combinations of other mechanisms, such as clay electro-chemical actions. You can see that's as far as I have progressed in soil chemistry.
To use the theory of capillary action you need an air-water interface and that is not always the case for frost action.
RE: Frost propagation
I think frost heave has something to do with grain size, void ratio, water content, and temperature. It is not true that soil will frosen wherever it has the potential for capillary action, the depth counts. Surface water in soil with lots of fines tends to perform worser than uniform coarser soil because of smaller/tighter void ratio - lack of space to accomodate the volume expansion, or particle realignment (by roll over).
The expansion should be all around with the fast, and the most in the direction of sharpest temperature drop.
Chemistry? Oh, my worst enemy. But I believe it has something to do with water attratciveness (affinity) of soil of different types.
RE: Frost propagation
RE: Frost propagation
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Jim Houlette PE
Web: www.evstudio.us
Online Magazine: www.evstudio.info
RE: Frost propagation
Behind a cold wall, the heat flow can be horizontal, and the ice lenses vertical, so the wall can be pushed laterally.
The same process can form ice lenses parallel to a slope. When the soil melts, the slope sloughs.
RE: Frost propagation
Therefore, not only is it important where the cold front is, but also the ability of the soil to draw in additional water which increases the level of heave.
For the first time in years, with the cold winter in the UK we are seeing frost heaving of pavements, so bit of a 'hot' topic at the moment.