ABSTRACT
The constant lack of free building areas may lead to set up constructions and infrastructures on unstable zones. Slow landslides can be dangerous when their speed increases, as the phenomenon often announces an imminent failure. The site of ‘‘Petit Caporal’’ that has been studied for nearly thirty years by the technical services of French State is precisely one of these slow landslides. Further research may allow to identify better their real physical meaning and to determine how the scale changes between laboratory tests and a real landslide should be taken into account. Fixing t comes down to the hypothesis that the observation period is very short in comparison with the complete lifetime of the landslide. In the case of the ‘‘Petit Caporal’’ landslide, the variable s directly expresses the influence of the piezometric changes on displacements. It allows determining how the material might be subjected to creep.
