The structure and mechanical properties of river and lake ice

The purpose of this paper is to relate the mechanical behaviors of seasonal lake and river ice to their grain structures. It is shown that for the lake ice the grain structure, and resulting mechanical properties, vary through the thickness of the ice and depend on the proximity to the shores and water inlets. The mechanical behavior of this natural ice is compared to that of S2 ice under similar loading conditions both in terms of strength and fracture mode. We conclude that while fracture models and strengths inferred from tests performed on laboratory-grown S2 ice can be used to provide strength estimates for accretion river ice, their use for the bulk of most lake ice covers is problematic due to microstructural differences between the two kinds of ice.