Failure of Volcanic Slopes in Cold Regions and its Prediction

The aim of this study is to reveal failure mechanisms of volcanic slopes in cold regions and to propose a prediction method on the failure. To achieve the purposes of this study, a full scale-embankment and -cut slope, which was 5 m in height, 12 m and 4 m in length and the angle of 45 degree, were constructed. A typical volcanic soil in Hokkaido as soil material was adopted. After the constructions of embankment and cut slope, the changes in soil moisture, temperature, pore pressure in the embankment and the cut slope were investigated using monitoring devices such as soil moisture meters and so on. Simultaneously, a series of model tests was performed on small size slopes constructed by the same soil material and compaction conditions as that in the real field. In consideration of the results of model test and field monitoring, it was found that the slope failures can be uniquely assessed by the changes in water content in zones subjected to rainfall and freeze-thaw actions.