Author(s): Melanie Schachter; Don Spencer
Linked Author(s):
Keywords: No Keywords
Abstract: Ice fragments in a river, strait, or lake may also form arches either at natural restriction points or at man-made restrictions such as bridge piers. Arching of fragmented ice floes between bridge piers often leads to the formation of ice jams. The formation of an ice jam can result in extensive blockage of the free stream and lead to flooding. In other situations. the formation of jams may restrict navigation. There are few field data on the controlling parameters initiating the formation of an ice arch (Gerard, 1984), although small scale experiments have been made in flume tanks using synthetic ice (Calkins, 1978; Tatinclaux et. aI., 1978) and refrigerated ice (Tatinclaux et. aI., 1978). These studies have limited themselves to simple geometric representations of the floes and only one or two floe sizes were tested. Nevertheless, experiments do provide some very useful insight into the parameters controlling ice arch formation. One of the main shortcomings of these studies is that the internal friction between floes may not have been correctly modelled. This is especially true for the studies using synthetic ice. In an analytical study by Sohdi et. aI., 1978 the ice was treated as a granular Mohr-Coulomb material and theory derived from soil mechanics was applied. Comparison of the model with large scale arching events showed reasonable agreement. In this case, the use of a granular type model seems valid because the floe size was much smaller than that of the restriction.
Year: 1994