Abstract: Based on laboratory tests on the silty sand in Guangdong, we researched on the permeability, deformation and strength of the silty sand, and discussed its stress-strain relationship and parameters of Duncan model. Results show that the soil is of low permeability and medium compression and extremely high shear strength under a high degree of compaction and cementation. The stress attained an obvious peak value and then decreased sharply with the increasing strain. Under shear stresses, the soil exhibited shear contraction, and then when the deformation increased to a certain value, the soil displayed shear dilatation features. What’s more, Duncan model can be used to describe the constitutive relation of the soil. The research results will provide foundation and basis to solve engineering problems of silty sand.

Key words: silty sand, mechanical behavior, stress-strain relationship, Duncan model