Journal of Cold Regions Engineering

This paper summarizes the results of a series of punch tests conducted on freshwater ice rubble at the University of Calgary. The main objective of the tests was to approximate the in situ punch tests in such a manner that failure behavior of the ice rubble and the effect of different parameters could be studied. The tests were conducted in a rectangular Perspex tank, which simulated the plane strain mode and made it possible to observe and record the failure process. The first set of tests provided considerable insight into the behavior of rubble ice, but it was clear that a more rigorous test program was required. For the second test series, the equipment was improved so that it provided a better control over speed and less fluctuations in the recorded loads. A summary of the collected data regarding the strength properties is presented and the observed behavior is discussed. It is concluded that using video photography and a 2D test arrangement has provided invaluable insights into the behavior of ice rubble. These included the observation that the failure behavior depended on the loading rate. The observations obtained from the low-speed tests support the use of geotechnical anchor plate theories for the interpretation of these results.

This paper presents generic equations and analyses of a cylindrical pontoon boom's capacity to retain ice. The presentation arises out of actual booms deployed on the St. Lawrence River downstream of Montreal but are valid for any cylindrical ice boom deployment. The boom's retention capacity not only relates to the pontoon's dimensions but also directly relates to the ice sheet's characteristics including thickness and strength. The role of friction and the geometry of the ice at the interface of the pontoon also determine the behavior of the structure and the associated line loads that develop. The analyses of environmental load show that the traditional theory of ice, acting as an aggregate, cannot explain observed values. Instead, this paper suggests that the ice upstream of a boom is a relatively coherent sheet. The internal strength of the ice sheet is compared to the environmental forces and the boom's capacity. These analyses improve understanding of the observations of the St. Lawrence booms made over the last 30 years.

This paper summarizes the results of an investigation of mechanized support under permafrost conditions. The present paper analyzes mechanized support behavior under subzero temperatures. The influence of cooling of the working fluid on support resistance is considered, and recommendations are given for efficient operation of mechanized complexes under those conditions. The laboratory experimental data are in good agreement with the results obtained from a field study.