Abstract
Landslides are classified into two types, a new landslide and a recurrent one. We observe the formative traces of slide surface in the weathered Tertiary layer found in one of those test pit we are concerned with. The movement of a landslide surface triggers the transformation of a new landslide into a recurrent type; in other words, a slide surface, starting with the physical features of fissures in strate, changes into a continuous plain stretch, which leads to the formation of soft and thin-layered clay.
The formation of clay is due to the absorption of moisture and disturbance of the slide surface, and those phenomena are related to the content of Smectite. So the dynamic properties and forms of landslides vary according to types of landslide.
Primary emphasis should be placed on the determination of type of a landslide in terms of a stability analysis of its surface.
