LABORATORY SHEAR TESTS ON VISCOUS NATURE OF LIQUEFIED SAND

摘要

The rate dependent nature of liquefied sand was investigated by laboratory shear tests. Sicne previous experience has revealed the many difficulties inherent in maintaining the state of liquefaction of a sandy specimen, new measures were attempted. The test results indicate that the measured shear stress consists of frictional and rate dependent compo- nents, and a viscosity coefficient was assessed from the later component. The measured viscosity varies with the rate of strain as well as the magnitude of strain itself. A similar test on a dry specimen revealed less viscosity and implied that a major part of rate dependency comes from the behavior of pore liquid in the case of water-saturated sand. It was in- teresting, moreover, that sand with fines was of less viscosity. Finally, a numerical analysis was conducted on a real liquefaction-induced ground deformation and the results were consistent with the observation. liquefaction -induced ground deformation and the results were consistent with the observation.