Experimental study to evaluate the effect of particle size on the small strain shear modulus of coarse-grained soils

Abstract

Abstract Coarse-grained soils are found commonly in nature and are extensively used for a wide range of engineering applications, such as slopes, earth dams, and railway foundations. This study presents an experimental investigation on the effect of mean particle size D50 on the small strain shear modulus Gmax of coarse-grained poorly-graded and well-graded soils. Combined with particle morphology analysis, a series of shear wave velocity tests were performed on pure sand, pure gravel and sand-gravel mixture specimens by taking advantage of a torsional vibration measurement device in a large scale triaxial apparatus. The results demonstrate that Gmax is insensitive to D50 for uniform sand and gravel specimens. On the other hand, Gmax increases gradually with D50 for well-graded sand-gravel mixture specimens. The discrepancy in the relationship between Gmax and D50 for poorly- and well-graded soils is related to the degree of size polydispersity in the specimens.