Experimental Investigations Of Ice Breaking By A Moving Load

The problems of ice breaking and the use of ice sheets as a runway and a load carrying platform are of great importance in developing the continental shelf. Various dynamic effects, which appear when a load is moving along an ice sheet, considerably reduce the carrying capacity of the latter and decrease the amount of energy needed for ice breaking due to the resonance phenomena. That is why the problem examined in this paper is particularly important in two aspects: for the calculation of safe loads and modes while accomplishing engineering works on ice sheets; and for using the bend-gravitation resonance as a means of ice breaking to prolong navigation and to struggle against ice difficulties. The paper deals with the second aspect, i.e. the possibility of the resonance way of ice breaking. This method implies the breakup of an ice sheet by the bend-gravitation waves of resonant velocity. Under the bend gavitation resonance, the ice is deprived of water support, and minimal energy is required to break it. This feature of the proposed method makes it perspective for ice breaking. The problem of estimating the carrying capacity of an ice sheet under dynamic loads is developed in many theoretical and experimental investigations. But we think all those papers simplify the problem, since the theoretical calculations usually stop after finding stresses equal to the ice breaking point. Accordingly, the experimental investigations generally stop when cracks appear in ice. But the experiments show that this approach turns out to be useful only for either defining safe loads or a few cases of loading ice sheets (e.g. loading at the free edge of an ice sheet). But in general, when the problem of ice breaking is being solved, the above mentioned procedure gives definitely reduced breaking load.