Erodibility characterisation for suffusion process in cohesive soil by two types of hydraulic loading / Hong Haï Nguyen in La Houille blanche, N° 6 (Décembre 2012)  

Erodibility characterisation for suffusion process in cohesive soil by two types of hydraulic loading [texte imprimé] / Hong Haï Nguyen, Auteur ; Didier Marot, Auteur ; Fateh Bendahmane, Auteur . - 2013 . - pp. 54-60.
Hydraulique
Langues : Anglais (eng)
in La Houille blanche > N° 6 (Décembre 2012) . - pp. 54-60

Mots-clés :	Geotechnical engineering Erosion sensitivity Laboratory experiments Suffusion Energy Clayey sand
Résumé :	An experimental program was set up to study the suffusion process by using a triaxial erodimeter developed in our laboratory. This device is equipped with a multichannel optical sensor in order to characterize precisely the initiation and development of suffusion process. With the objective to characterize the erodibility of clayey sand, tests were performed under either flow-rate-controlled or hydraulic-gradient-controlled conditions. The test analysis allows distinguishing three steps. First, suffusion of a small quantity of clay is detected on downstream. In flow-rate-controlled conditions, this suffusion is immediately followed by a high increase of the hydraulic gradient which continues during the second step. The second step is characterized by very low amount of particles in the effluent. During the third step, high suffusion of clay appears and induces erosion of clay and sand. The results reveal the necessity to take into account the evolutions of hydraulic gradient (or pressure gradient) and also the evolutions of velocity (or flow rate) to represent the hydraulic loading. The analysis based on energy expended by fluid flow and eroded mass permits to characterize the soil sensitivity to clay suffusion and clayey sand erosion for tests under the two types of hydraulic loading.
ISSN :	0018-6368
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