Abstract
Many model shaking tests to date have suggestedextremely high strain-rate dependency in the rigidity and strength of liquefied sand. The present stud conducted, firstly, torsion shear tests in which liquefied specimens were subjected to monotonic shear at a variety of strain rates. Different from model tests, the present test results did not indicate rate dependency. In the second stage, moreover, the limited magnitude of strain in the above-mentioned tests were overcome by developing a new testing instrument. Tests on specimen of Styrofoam grains, which had very small buoyant unit weight in water did not exhibit rate dependency either.
