colmatage minéral secondaire

OBS: colmatage: Accumulation des fines particules du sol entraînées par l'eau dans les pores d'un matériau drainant, naturel ou artificiel, le rendant progressivement incapable d'assurer sa fonction.
OBS: D'une manière générale, la stricte application des critères de filtration définis par les divers organismes nationaux prend en compte les effets à long terme du colmatage minéral et donc limite les risques de non-fonctionnement des réseaux de drainage.

CONT: The mineral clogging mechanism. Due to the drag force of the water at the interface between the soil and a drain pipe, soil particles may be carried into the pipe via its slots. This process can never be prevented completely, but can be counter-acted by installing an envelope material, often geotextile, around the drain. Generally, two types of mineral clogging can be detected which are referred to as primary and secondary mineral clogging. Primary clogging is a consequence of the sudden drastic changes in the soil/water boundary conditions, caused by the installation of the subsurface drainage system, and the resulting water flow, including particle transport due to the high hydraulic gradients, towards the newly installed pipes. Secondary clogging is defined as particle transport into filters and/or pipes, in the long term; ...