Compression Behaviour of Chlef Sand and Transition of Fines Content Using Pressure-Dependent Maximum Void Ratios of Sand

This paper presents a study on Chlef sand to examine the effect of fines content (F_c), relative density (RD) and initial conditions on the compressibility behavior. The interpretation of the results is based on the concept of the intergranular voids ratio (e_s) and two hypoplastic parameters model Hs and n for calculation of the maximum voids ratio. The œdometric tests results made in the laboratory show that the fines content transition (F_ct) of Chlef sand is in good agreement with the results published in the literature. The results obtained indicate that the higher value of fines fraction (F_c) in the sand cause an increase in the compressibility coefficient (C_c) and the granular compressibility coefficient (C_c-s). Moreover increasing the density from 65 to 80% decreased both coefficients (C_c) and (C_c-s). The samples prepared with the moist tamping method (w = 3%) have compressibility coefficients greater than samples prepared by the dry pluviation method (w = 0%). We have shown that the fines content transition (F_ct) depends on the initial state of the samples (relative density, preparation method and maximum void ratio). Finally the granulometric characteristics (D₁₀, D₅₀ and C_u) have a significant effect on compression behavior. Nevertheless a good exponential correlation has been found between the compressibility coefficient (C_c), the granular compressibility coefficient (C_c-s) and the effective diameter (D₁₀), the average diameter (D₅₀) and the uniformity coefficient (C_u).