Shear Strength Regain of Clayey Landslides and Remedial Works.

The shear strength regain effect takes place whenever an intermittent landslide on clayey materials occurs. During the rest period, the clay material nearby the sliding surface regains part of its shear strength. The new strength level can overcome the residual shear strength by more than 20%. The more is the rest period, the more is the shear strength regain. A new movement will take place only if the hydraulic conditions will be able to exceed the new level of shear strength. The paper examines closely the shear strength regain phenomenon, analysing the results derived from several dedicated ring shear tests on clayey landslide materials, and deals with some case studies which, taking into account the positive effect of the shear strength regain, provide us a new approach to bet-ter design the remedial works on clayey landslide.