1962 Volume 3 Issue 1 Pages 19-25
The author carried out unconfined compression tests on undisturbed samples of landslide soils having slip surfaces.Test pieces were polished with steel-wool and cloth after tests, to observe their stratification.Soil layers having slip surfaces in situ were observed as layers with anisotropic black varves or with dominant boundary between clayey layer and other layers.Unconfined compression failure planes in each test piece had relations to locations of layers or boundaries.Shear stress on the first appearance of failure on the planes were smaller than that on other planes.