ABSTRACT
Many landslides have occurred on Mikabu belt in Shikoku Island. In this Paper, the influence of the clay minerals on strength characteristics of the landslide clay in Mikabu belt whose mother rock is green rock were investigated. The green rock is very weak and easily weathered. The main clay mineral of Mikabu green rock and its weathered clay is chlorite. There are two kinds of chlorite in it. One is chlorite and the other is expansive chlorite. The other clay minerals of green rock and its weathered clay are the montmorillonite, the quartz and feldspar. The strength parameter of landslide clay containing the quartz and the feldspar at the peak and residual state was large, and that of containing the expansive chlorite or the montmorillonite was small.
