Abstract
The authors are measuring rain intensity, suction, volumetric water content, shear strain and lateral flow in a natural granite soil slope in Hatsukaichi City, Hiroshima Prefecture. In August, 2014, the fourth record was provided in history of observation as amount of rainfall in August due to the 12th and 11th typhoon and the heavy rain on 20th August. In this paper, we report the observations under different heavy rainfall and initial moisture conditions in August, 2014, and the influence of rain intensity and initial moisture conditions on rain infiltration and shear deformation were examined by the comparisons of temporal changes and amount of soil moisture during rainfall. As a result, the increment of volumetric water content is bigger as soil moisture conditions become more drying. Similarly, lateral flow and shear deformation have a tendency to become larger as increment of volumetric water content is bigger, but in a small rain, shear deformation decrease with decreasing volumetric water content.
