Author(s): Hung Tao Shen; Desheng Wang
Linked Author(s): Hung Tao Shen
Keywords: No Keywords
Abstract: The critical velocity, or critical Froude number criterion has long been accepted as a means of determining frazil jam profiles. Field observations, however, indicated that the value of the critical velocity not only varies from river reach to river reach but also from time to time in a given reach. This clearly shows the deficiency of the critical velocity concept. The transport of frazil particles on the underside of an ice cover is similar to the transport of bed sediments in an alluvial river; the difference being only that in one the buoyant force exceeds the gravity force while in the other the reverse is true. Frazil particles are generally transported along the cover in the form of the cover load. In this paper, the concept of ice transport capacity is developed based on the field data obtained from the Hequ reach of the Yellow River. The analysis of field data shows that the ice transport capacity can be described by existing bed load transport formulas for low density sediments. Laboratory experiments are carried out using low density chips to determine their transport rates under both open water and ice-covered conditions for a wide range of flow conditions that are useful for frazil transport. A cover load transport formula is obtained based on field and laboratory data.
Year: 1992