Author(s): Ken-Ichi Hirayama; Joachim Schwarz; Han Chin Wu
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Keywords: No Keywords
Abstract: Experimental investigations of ice forces on vertical structures have been performed at the Iowa Institute of Hydraulic Research of the University of Iowa since 1970. Details and findings of the research, such as model test facility, similarity considerations, scale effect, and fracture mechanism of the ice in front of the pile were already reported. This paper describes the further progress of the research. The fracture mechanism of the ice cover in front of the pile was thoroughly investigated by an application of strain gages frozen in the ice cover. Experimental results of the effective ice pressure on rectangular and circular piles of various diameters are shown for the indentation type of ice-pile interaction. The difference between the indentation and penetration ice pressure is thus clarified and an empirical power relation between indentation ice pressure and pile diameter is proposed. Measurements of indentation depth corresponding to the occurrence of the maximum ice pressure showed little dependency on the pile diameter. This led to the application of a theory proposed by Carothers for the relationship between ice pressure and pile diameter. The effect of the degree of contact between ice and structure on the effective ice pressure was also investigated and found to be a function of strain rate, pile diameter, ice thickness and shape of the pile as well as of the ice temperature.
Year: 1975