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Coefficient of Friction

Coefficient of Friction

Coefficient of Friction


I am looking to calculate the lateral loads applied from a pit of manure. Do I follow the normal procedure as if it was normal backfill where i can search for the coefficient of friction? Is there a coefficient for manure? Thank you!

RE: Coefficient of Friction

You may be able to obtain information from an agricultural department. Back in first year engineering, my cousin was studying agricultural engineering at the U of Man. I had a crest fabricated using the same logo as the faculty of Architecture, but with Agriculture on it...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates


RE: Coefficient of Friction

Are we talking solid or liquid manure? Also, is the structure below grade?

In general, if we are talking about a below grade structure, the worst case condition will be when it is empty and only dealing with structural loads on the exterior wall due to the later pressure of the soils (possibly hydrated) and induced loads due to traffic.

If we are talking about a solid manure pile on a above grade structure, the worst case condition would be the manure piled up along the structural wall of the building (note, you may be required to maintain a freeboard (e.g., 0.5') and not stack to the rafters. A 3 (horizontal):1 (vertical) slope is a conservative estimate for any piles of manure (or at least that is what Indiana uses) for determining maximum volume of wastes in an area.

RE: Coefficient of Friction

Your key issue is defining what your particular "manure" is.

This could be a mixture of relatively stiff straw and more solid errrr horse shit or could ba complete liquid gloop like you get underneath a slatted shed with cow effluent.

So I think you need to look at both extremes, I.e. a pile of manure which could stand up as a heap, so an internal friction angle of maybe 25 or 30 degrees or one which is essentially heavy water.

I doubt that manure behaves in anything similar to a pile of aggregate and is probably plastic in nature and settles over time creating more dense material than when it starts. So again look at two extremes if you can get the data.

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