Long-Term One-Dimensional Compression Tests and Fractional Creep Model of Compacted Snow

Compacted snow is a primary construction material in polar regions and experiences persistent deformation during loading, which considerably affects the safety of snow structures. This study conducts a series of one-dimensional compression tests to investigate the effect of initial densities and stress levels on the long-term deformation of compacted snow samples over 90 days. The compression curve of compacted snow can be divided into three stages: instantaneous, primary, and secondary compressions. Instantaneous compression occurs at pressurization; primary compression occurs within 10 to 40 min of loading; secondary compression occurs when snow remains unstable for 90 days. Secondary compression is the main cause of long-term deformation of the samples and the secondary compression coefficient tends to decrease with a higher initial density and lower normal pressure. A fractional creep model is developed to describe the experimental data and a good agreement was obtained. The proposed model adopts the fractional deviation approach to modify the classic Burgers model, and the density-dependent parameters are calibrated using the experimental data. The proposed model is verified as a useful tool in describing the creep behavior of snow, and the results of this study contribute to the safe operation of building structures on snow foundations.