An investigation on progressive failure in granular slopes leading to flow-like landslides

Rainfall-induced flowslides in loose granular slopes involve many and different geomorphological contexts causing heavy economic and human losses. Usually the triggering mechanism is associated with suction reduction or increase of the groundwater level. During rainwater infiltration sloping soils may experience a non-uniform stress field possibly leading to progressive failure. In special cases, this can trigger mechanisms of undrained instability leading to rapid flow-like slope movements. In spite of the severity of the consequences of such phenomena, little attention has been paid until now to this problem. This paper is aimed at providing a contribution on this topic by some results of experiments conducted on small-scale slopes consisting of loose sandy soils subjected to artificial rainfall.