Experimental Studies of Sea and Model Ice Fracture Mechanics

We study ice fracture mechanics based on loading experiments with the floating ice beams with fixed ends. Both natural and model ice properties were investigated. Full-scale field works were performed on sea ice of the Svalbard Archipelago. We also performed model ice studies of two ice types in the Ice Basin of the Krylov State Research Centre (KSRC) in St. Petersburg: fine granule and columnar. In the experiments, an ice beam was cut in the ice cover, both ends of which were kept attached to the surrounding ice sheet. Then a horizontal force perpendicular to the side surface of the beam was applied to the middle section of the beam. For these purposes, the vertical cylindrical indenters with a diameter of 0.15 and 0.02 m were used both in field and model conditions. The indenters provided the force application through the whole ice thickness. The natural ice thickness range from 0.4 to 0.6 m; the model ice was 0.05 m thick. The beam width was almost equal to the ice thickness while the beam length varied from 2 to 8 ice thicknesses. The visual observations and the force-time records allowed tracing qualitative patterns of the beam failure process. We measured the breaking force dependence on the ice type and ice beam geometry. The beam tests described here allowed us to find the relationships of various strength parameters of ice crushing, compressive and tensile strength, as well as to compare the behavior of natural and model ice under identical loading conditions.