Abstract
The shear strength characteristics of clay forming slip layers of fractured zone landslides are investigated by triaxial tests. The angle of shearing resistance φ′ on the landslide clay does not change with remoulding. The angle of shearing resistance of landslide clay, approximately 25°-30°, is smaller than one of marine clay in Japan. This is one of the reason which the landslide occurs at gentle slope. The value of c′ on the normally and over consolidated specimens is zero. Therefore, the main factor of landslide is the increase of the pore water pressure.
The clay minerals are investigated by X-ray diffraction method. Absorbed ions are assayed by absorptimetry. It was cleared that the gradation, clay minerals and absorbed ions have influence on the strength characteristics of landslide clay.
