Abstract
A large rock slope failure, such as landslide, has heavy influence on the construction and maintenance of public structures in Japan, which is mainly consist of mountainous, hilly regions. There have been much conducted the investigations and countermeasures of the rock slopes after their movement had occurred, and the useful knowledge of rock slope stability has been accumulated through those experiences. But, because the method to specify an unstable slope among many slopes before their movement occur has not been established yet, we are often troubled with the situation to judge whether more detail investigation for the slope will be necessary or not.
In this study, the geographical and geological features of rock slope failures were clarified collecting by indoor and/or field exploration from the about 100 samples of unstable rock slopes. Also, a numerical rating system to specify an unstable rock slope and to evaluate the stability of it was proposed based on above features
