Abstract
The surface geometry of a landslide, which is defined by the shape, orientation and depth of a slide surface or zone, is essential for stability analysis and for the design of remedial works. This note sets out to demonstrate the accuracy of a technique that utilizes the field surveying of surface displace ments to presume the position and shape of the underlying slide surface.
The technique designated as “polygonal method” presumes the slide surface profile beneath a landslide by a polygonal approximation on the projective plane parallel to a direction of landslide movement.
The accuracy of the technique is examined against results of Komoro landslide analyzed by the method of rotational slide assumption and Narao landslide precisely located by a number of field borehole tests.
