Vehicle bearing capacity of frozen ground over a soft substrate

Abstract

Freezing temperatures may allow the use of vehicles and heavy equipment on otherwise inaccessible or sensitive areas such as swamps, bogs, tundra, and peatlands. Predicting operable conditions on frozen ground is useful for forestry, mining, oil exploration, construction, and military operations. Guidelines for estimating the frost depth necessary to support a given vehicle load have been generated based on experience in forestry operations on peatlands and similarities in the strength behavior of frozen peat and frozen soils. Correlation with information in the literature leads to a simple equation relating safe trafficability of frozen ground over soft ground: P = Cz2, where P is the maximum load and C is a constant depending on the strength of the frozen layer, which has a thickness z. Values for the constant C and a chart showing required frozen thickness for a variety of vehicles are given. Key words : bearing capacity, frozen ground, peat, frost, vehicle mobility, strength.