Washboard road

This set shows images and movies of an experimental realization of washboard road --- the annoying instability of a flat sand or gravel road under the action of driving wheels that causes it to develop ripples or bumps.

There are several versions of the experiment. In the Cambridge version, a wheel rests on the edge of a rotating table with a bed of sand around the outside. In some experiments, the wheel is replaced by a simpler plow blade. In the larger Lyon version of the experiment, the wheel or plow is at the end of a rotating arm.

Washboard or "corrugated" road is also observed on railway tracks, where wear rather than material transport is involved.

Collaborators:
Anne-Florence Bitbol
Nicolas Taberlet
Jim McElwaine

See
www.physics.utoronto.ca/nonlinear/papers _sand.html

For a real washboard pattern, see
www.flickr.com/photos/12604020@N05/35466 90933/