In this study, we investigated the effect that the quality of accumulated snow on the snow's resistance to sliding. First, we observed changes in the quality of snow that had accumulated on the roof of a building. It was found that the particle size of the snow increased to approximately 2mm after one week and that the water content of the snow increased. Next, experiments were conducted to determine the effect that particle size of snow on a sloped roof has on the snow's resistance to sliding. The results showed that the resistance to sliding decreased as the particle size of snow increased (i.e., as the snow became more granular). The effect of particle size on the snow's resistance also depended on the degree of snow melting. From the facts described above, it is possible to utilize the effect of particle size on the snow's resistance for control of snow sliding on a sloped roof.
