ABSTRACT
Consequently, a marked reduction of effective horizontal stresses in the dam body may occur, thus increasing the risk of particles migration.
To safeguard the core (base B) material and avoid the progress of erosion, a protective transition (T ) must be correctly designed; its voids, related to the grain size distribution and porosity, must be sufficiently small to stop the migrating B particles within short distances, thus avoiding limit states related to backward erosion leading up to flow pipes generation; (T ) must also allow a safe drainage of B, to avoid limit states as clogging and blinding, inducing in turn uncontrolled increases of pore pressures.
