0
$\begingroup$

Consider a conical pile of sand (or any other granular material) that is placed on a flat surface. This conical pile has a given radius and height (r and h, respectively). What would the effect be on the conical pile of sand when the flat surface is tilted at an angle $\alpha$?

This would be in terms of whether the granular material would avalanche, partially avalanche or remain still. How could we predict when these cases occur for different values of $\alpha$?

The papers I have found are to do with the formation of a pile of sand at the angle of repose, but not much about the actual pile of sand on an inclined plane.

Improve this question
$\endgroup$

2 Answers 2

Reset to default
0
$\begingroup$

Consider an imaginary inclined plane that passes through a pile. The part of the pile above it is just a normal pile.

The question is what happens when such a pile sits on another surface. Piles are supported because grains interlock or have enough friction to prevent motion. One might expect a rough surface or a surface with a lot of friction to support the pile.

A smooth, low friction surface would not support the pile. But I cannot offer any more detail than that.

Improve this answer
$\endgroup$
1
  • $\begingroup$ Would there be a way to perhaps mathematically quantify the change in shape of a pile? We need quite a few constants like friction coefficient of the surface, and the cohesion of the material itself, but could an approximate elongation of the cone be estimated based on the angle of inclination, along with the various other given variables such as material properties, friction coefficient, and dimensions of pile? $\endgroup$
    – K.R.
    Commented Jul 18 at 13:52
0
$\begingroup$

The 'angle of repose' is the limit of stability for a granular pile. A pile that takes on a conical shape according to the angle of repose, has slumped into that shape.

Tilting the base under such a pile raises the slope on one side of the cone, but lowers the slope of the other side. Presumably, the raised-slope side will slump to the angle of repose against its new horizontal, while the lowered-slope side will not be disturbed (it's a bit flatter than before, but that just means it's under the angle of repose, therefore stable).

Because the new pile is differently sloped on its flanks, it is no longer a cone, and base/height measurements are not a complete description of the new shape.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.