Processing snow for high strength roads and runways

Abstract

Using a variety of conventional snow processing equipment in deep snow fields in West Yellowstone, Montana, we studied snow processing techniques having the potential for producing high-strength snow roads and runways. The test location and timing were selected to obtain snow properties and winter ambient temperatures as dry and cold as possible, in a convenient location, to simulate conditions in polar regions. Four separate test sites, each with a different treatment, were established using the snow processing equipment. Observations were made for 12 weeks after construction to monitor the snow's hardness (strength) and its temperature distribution. Plane sections were taken at each site on a weekly basis to allow comparison of bond density and strength. We also used image analysis to find which critical microstructural properties correlate best with compressive strength changes. Temperature data were also correlated with strength changes. Test results indicate that a powered tiller with a relatively dense tooth population provided the highest strength snow. This snow was strong enough to easily support contact loads greater than 700 kPa, which could allow the use of conventional aircraft and wheeled vehicles in areas of deep snow.