Predicting the saturated hydraulic conductivity of particulate assemblies based on active fraction of fines and particle-size disparity parameters

The hydraulic conductivity parameter of soil deposits represents an important indicator in the different soil mechanics studies (stability analysis, settlement, drainage, seepage) and it is commonly related to several influential physical factors as fines fraction, gradation, particle shape and size, porosity etc. In this context, this paper intends to predict the hydraulic conductivity based on the intergrain contact state in terms of active fraction of fines (b) and particle- size disparity (x) of particulate assemblies. To achieve this goal, a series of constant head permeability tests were carried out on reconstituted Hostun sand-silt mixture samples in the range of 0- 40% fines content at three different initial relative densities (D-r = 20%, 54% and 90%) to measure the saturated hydraulic conductivity. The obtained results indicate that the normalised fines content (f(c)/f(cthre)), the disparity of size ratio and the active fraction of fines ( b) could be considered as reliable parameters in the prediction of the sand-silt binary assemblies saturated hydraulic conductivity response (R-2 >= 0.94). Moreover, it is found that the saturated hydraulic conductivity decreases with the increase of the equivalent void ratio proposed by (e*(Rahman et al.2008)) and Nguyen (e*(Nguyen et al.2017)) of the studied materials.