Effect of frost on sheet pile wall in saturated clay

[jonastp]

Hello,

I'd like to hear your opinion on the effect of frost on a sheet pile wall (internaly braced) in saturated clay. Should the soil pressure be multiplied by a factor (like 50%)?

Any of you have experiences of such case that you could share?

Thank you very much,

Jonathan

 

[jayrod12]

I would be concerned with the frost trying to push the sheet piles upward out of the bottom of the excavation more than a significant increase in lateral pressure. But I'm no geotech.

 

[GeoPaveTraffic]

I have never applied such a correction or seen it applied by others.

Mike Lambert

 

[aeoliantexan]

If it stays cold enough long enough, there will be freezing behind the wall. The freezing will progress laterally, at right angles to the wall, and ice lenses can form parallel to the wall. This can subject the wall to additional pressures, conceivably up to passive.

I once saw the walls of a reinforced concrete pit under a truck scale bowed inward until they pinched the platform and rendered the scale useless. When the pit was demolished and the surrounding soil excavated, what is described above was evident. This was in northern Iowa. The frost had penetrated laterally about two feet from the wall. Away from the pit, the vertical frost penetration was about three feet.

In another case, the floor of a freezer room in an ice cream plant was heaved about 8 inches over a period of years by ice lenses in fat clay. Even more interesting, when the soil was thawed, the floor settled 16 inches.

I can't guarantee that the wall will be affected, but if the potential consequences are severe, insulating it would be wise.

 

[killswitchengage]

Well according to Terzaghi , frost susceptible soils are only in a given range of particles diameter . Mostly silt and fine sand are to be feared , clays tend to be neutral only if the action of the water itself is absent