Abstract：Circulating flow characteristics are typical characteristics of dilatant sands in liquefaction stage. In order to study the dynamic shear behavior of liquefied circulating soils, fine particles of different contents were added to sandy soils with skeleton relative densities of 35%, 50% and 80% respectively, for the purpose of changing the gravity of liquefied flowing soils. The variations of shear modulus and damping ratio of liquefied flowing soils with different skeleton densities and different contents of fines in large deformation stage were studied by cyclic torsional shear test. The test results show that the liquefaction circulating flow soil still has a certain modulus in the stage of large deformation, and the modulus decreases gradually with the increase of strain; the modulus at the stage of flow deformation is basically independent of the weight of liquefied soils; the modulus at the stage of strength recovery is closely related to the content of fines and the relative density of skeleton; the unloading modulus at the stage of large liquefaction deformation tends to be stable, and its stability value is about 35% of the initial unloading modulus; damping ratio increases first with the increase of shear strain, and decreases with the development of shear strain when soil reaches initial liquefaction. For soils with the same skeleton density, the phase transition angle decreases with the increase of the content of fines, and the slope of critical state line increases with the increase of the content of fines.
