Consequences of scalping and scalping/replacement procedures on strength properties of coarse-grained gap-graded soils

Evaluation of shear strength characteristics of coarse-grained soils by performing laboratory tests resorts often to a scalping or scalping/replacement procedure due to the presence of oversized particles in comparison with the device size. This work aimed to study consequences of these two procedures on the resulting shear strength characteristics. Experimental tests were performed on soils having gap-graded particle size distributions by using triaxial apparatuses with small and medium diameters Φ = 50 and 100 mm. Original soils were mixtures of fine particles (sand and glass beads) and coarse particles (two types of gravel). The original soils were scalped and (or) scalped/replaced by two different procedures. Different factors that influenced the mechanical properties of the scalped and scalped/replaced soils in comparison with those of the original soils were analyzed: ( i) the compactness parameter controlled for scalped and scalped/replaced soils, ( ii) the fine content of the original soils, and ( iii) the procedure used for the scalping/replacement.