Subsurface Drainage for Slope Stabilization

In saturated soils, drainage systems are one of the most effective remedial measures against slope instability due to their capacity to reduce pore-water pressure in the subsoil, increasing the shear strength of the soil. Due to their relative cheapness, subsurface drainage systems are widely used, also in combination with other stabilization works. Moreover, they provide a suitable solution to stabilization in a large number of cases, even when the landslide is very deep and structural measures are not effective (Popescu, 2002). In this paper the main subsurface drainage systems are described in terms of their conventional and innovative technologies, their limits and advantages. The design approaches in the relevant literature are also reviewed.