Abstract: Artificial snow compaction and sintering, which is the process of turning fresh snow into general snow, is a basic method for the construction of polar snow runway. Snow compaction densifies the snow pavement and snow sintering increases the bond size between snow particles and hence improves the strength of the snow pavement. In order to investigate the mechanism of the bond breakage evolution and stress bearing mechanism of the dense sintered snow under the unconfined compression test (UC), the three-dimensional discrete element method (DEM) was employed. A bond contact model for the sintered snow was introduced and the contact parameters were calibrated through published experiments results, firstly. Then, the discrete element model was established and the UCs were carried out; The DEM results are verified and the conclusions are as follows: (1) Intensive bond breakage occurs at the shear band of the dense sintered snow sample under UC, with bond fracture predominantly attributed to shearing under tension. (2) The crushing of snow particles affects the shear strength of the snow pavement, and the effect of high stress on the internal friction angle needs to be carefully considered. The study provides scientific support to predict the mechanical characteristics of compacted sintered snow under complex stress paths through simple in-situ tests in polar regions.

Key words: polar region, compacted snow, snow sintering, discrete element method, unconfined compression test