抄録
One of the purposes of this study is to get the internal information of slope, such as a thickness and profile of surface layer, from the information of landform and baserock geology. Another purpose is to investigate a fundamental method required to estimate the stability potential of slope when the surface layer thickness is known.
All data required for these purposes were derived from the reports of elastic wave prospecting carried out for public works. The results of statistical analysis of surface layer data may be summarized as follows:
The profile form of surface layer is in many cases either of uniform layer type or upper thicker layer type, depending on the vertical section form of slope. The thickness of surface layer is affected by the slope angle and baserock geology. From a large number of data on the relation between surface layer thickness and slope angle, the ultimate thickness and the mode thickness could be obtained in each slope angle. Assuming that the slope failure occurs preferentially at the surface layer with the mode thickness, the strength constant of the layer can be obtained by the reverse calculation based on the analytical method of slope stability. As a result of this calculation, it was proved that C' has an influence on the mode thickness of surface layer.
