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The threshold fines content of a sand with nonplastic fines represents the silt content where the soil transitions from being a sand matrix, with silt particles entirely contained in the voids between the sands, to being a silt matrix that contains isolated sand grains. A laboratory testing program was performed on a series of mixtures of sand and silt, with silt contents ranging from 0% to 45%, to determine if the friction angle, cyclic resistance, and normalized dissipated energy per unit volume required to initiate liquefaction changed based upon the silt content of the soil relative to the threshold fines content. These data were evaluated with respect to whether the silt content of the specimens was below the lower-bound threshold fines content or above the upper-bound threshold fines content. It was determined that soils above the upper-bound threshold fines content had lower friction angles, lower cyclic resistances, and required less normalized dissipated energy per unit volume to initiate liquefaction than soils below the lower-bound threshold fines content. It was also shown that under the larger strains experienced during monotonic testing, the friction angle did not reach a constant value until it was well above the upper-bound limiting silt content. Key words: threshold fines content, silt, dissipated energy, liquefaction, cyclic resistance. La teneur seuil en fines d'un sable a fines non plastiques represente la teneur en limon ou les sols passent d'une matrice de sable, ou les particules de limon sont entierement contenues dans les vides entre les sables, a une matrice de limon qui contient des grains de sable isoles. Un programme d'essais en laboratoire a ete effectue sur une serie de melanges de sable et de limon, dont la teneur en limon varie de 0 a 45 %, afin de determiner si l'angle de frottement, la resistance cyclique et l'energie dissipee normalisee par unite de volume necessaire pour amorcer la liquefaction ont change selon la teneur en limon du sol par rapport au seuil du contenu en fines. Ces donnees ont ete evaluees pour determiner si la teneur en limon des specimens etait inferieure a la teneur en fines du seuil inferieur ou superieure a la teneur en fines du seuil superieur. Il a ete determine que les sols au-dessus de la teneur limite superieure en fines avaient des angles de frottement inferieurs, des resistances cycliques inferieures et necessitaient moins d'energie dissipee normalisee par unite de volume pour amorcer la liquefaction que les sols au-dessous de la teneur limite inferieure en fines. Il a egalement ete demontre que sous les contraintes plus importantes subies lors des essais monotones, l'angle de frottement n'atteignait pas une valeur constante jusqu'a ce qu'il soit bien au-dessus de la limite superieure de la teneur en limon. [Traduit par la Redaction] Mots-cles: teneur seuil en fines, limon, energie dissipee, liquefaction, resistance cyclique., Introduction A laboratory testing program was performed on a series of mixtures of sand and nonplastic silt, with silt contents ranging from 0% to 45%. For each soil mixture, the [...]

The authors would like to thank the discusser (Dallo 2020) for his insights into their note 'Threshold fines content and behavior of sands with nonplastic silts' (Polito and Sibley 2020). [...]