THE INFLUENCE OF FROST ACTION ON THE BEARING CAPACITY OF FLEXIBLE PAVEMENTS

The frost heave in pavements would give damage in two forms: one is due to frost heave itself, while the other arises from the decrease in the bearing capacity of subgrade soil and subbase courses during the spring thaw. In order to protect pavements from frost heave damage, a number of methods are available. The most popular method presently used in Japan is to replace frost-susceptible soils with the local materials such as sand, volcanic ash or unscreened gravels. In the investigations, the bearing coefficients of the materials generally used in cold regions for subgrade, frost preventing layer and subbase course, were obtained from the buried plate-loading tests on each layer of pavements before the freezing and after the thawing periods at Bibi Test Road in Hokkaido. Based on these coefficients, the moduluses of deformation for the layers of these materials have been calculated using the approximate calculating method of multilayer-displacement for obtaining the stress-strain relationship in the pavements. (Author/TRRL)