Geohazard at volcanic soil slope in cold regions and its influencing factors

Abstract

This study examines the mechanism of the geohazards occurred at a volcanic soil slope in cold regions and its influencing factors in consideration of the effects of freeze-thaw actions on the physical properties, the water retention-permeability characteristics, and the deformation-strength characteristics of volcanic soils from the viewpoint of both experimental study and analytical study. To this end, we performed the long-term field measurement, model tests, laboratory element tests, and numerical simulations by taking volcanic soil slope subjected to freeze-thaw actions. As the results, this study revealed that there is a difference in the slope failure mechanism between cold region and warm-temperate region, and that freeze-thaw actions seriously influence thermo-hydro-mechanical behaviour of crushable volcanic coarse-grained soil slope under unsaturated condition even if the soil is a non-frost-susceptible geomaterial. Furthermore, this study clarified the mechanism, the endogenous factors, and the exogenous factors of the slope failure for volcanic soil ground in Hokkaido in comparison with the slope failure in warm-temperate regions.