Post-Liquefaction Torsion Shear Tests on Sand With Various Strain Rates

This text concerns with the deformation characteristics of liquefied sand which undergoes large residual deformation and flow failure. In particular, the nature of sand which can be used in a dynamic analysis of deformation in the time domain is aimed at. Although the former model tests have suggested a rate-dependent behavior of sand, a detailed measurement of stress and strain was not possible. This problem was overcome in the present study in which two types of torsional shear device were employed. A special care was therein taken to achieve such a large and realistic shear strain as 100% in a sample; Moreover, it was attempted to make the stress state within a specimen as uniform as possible after liquefaction by reducing the gravity-induced stress component. It was revealed that a specimen with very small effective stress does not have a rate-dependent nature when large shear deformation takes place