Equilibrium Thickness of Ice Jams

By equating the kinetic energy of ice floes carried by a stream to the potential energy they acquire when submerged, a relationship was derived between the mean velocity of the approach flow and the average thickness of the stable ice jam formed only by accumulation and transport of floes. This relationship was verified by experiments conducted in a refrigerated laboratory flume using real ice and plastic floes. The experiments also confirmed the theoretical prediction that there exists a maximum velocity of the approach flow beyond which no stable jam can exist. For deep channels, the corresponding maximum jam thickness was found to be approx 36% of the upstream flow depth.