[PDF] Aoe Laboratory Investigation Of The Mechanics And Hydraulics Of River Ice Jams eBook

Author :
Publisher :
Page : 118 pages
File Size : 32,95 MB
Release : 1976
Category : Ice on rivers, lakes, etc
ISBN :

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This report presents experimental results on the conditions of initiation of an ice jam by a simple surface obstruction, on the equilibrium thickness of an ice jam formed by accumulation and submergence of ice floes, and on the compression strength of floating, fragmented ice cover. In the study on ice jam initiation, it was found that the minimum concentration of floes in the opening of the obstruction at which a jam occurs is nearly independent of the ratio of width of constricted passage to channel width, and is proportional to a negative power of the ratio of floe length to width of constricted passage. From energy analysis of floe submergence, a relationship relating the thickness of a jam formed by accumulation and submergence of floes to the approach flow characteristics was derived and found to fit satisfactorily the experimental data. In experiments on compression strength of floating, fragmented ice cover it was found that the compressive strength is inversely proportional to compression velocity and independent of cover length.

Author : Mehmet Secil Uzuner
Publisher :
Page : 158 pages
File Size : 27,88 MB
Release : 1974
Category : Ice mechanics
ISBN :

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An analytical model is developed for evolution of embacles in rivers. The differential equations underlying the analysis are the static force equilibrium relation for the fragmented ice cover; the unsteady, nonuniform momentum relation for the liquid flow beneath the ice; and the unsteady continuity equations for the solid and liquid phases. The analysis is limited to the case of uniform, rectangular channels. It yields predictions for the streamwise distribution of the thickness of the ice cover and the depth of flow beneath it; the flow depth and cover thickness over the uniform downstream reach where the jam thickness and flow depth are constant; the flow depth at the upstream end of the jam; and the velocity of propagation of the jam front. Estimates are also obtained for the rate of growth of a jam during early stages of its evolution, just following initiation.

Author : A. N. Chizhov
Publisher :
Page : 106 pages
File Size : 16,72 MB
Release : 1974
Category : Dniester River (Ukraine and Moldova)
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This document contains translations of six articles dealing with ice jam phenomena on rivers. The articles indicate the quantitative tendencies in the formation of ice jams on the Dnestr River based on materials obtained from observations of past years, full-scale and model investigations, the results from studying the tendencies in ice jam phenomena in the tailwaters to the hydroelectric station, plus a procedure for calculating these occurrences; the authors also expound on the experience gained in modeling the movement of slush ice beneath an ice cover and the results obtained from aerial photographs of jams occurring on rivers.