抄録
Several series of multi-directional undrained simple shear tests were performed on saturated sand specimens, using a simple shear test device incorporating two pnumatic cyclic loaders in two mutually perpendicular horizontal directions. The load patterns employed were rotational in one type of test where cyclic stresses with equal or different amplitudes in two directions were applied with a phase difference of 90 degree. In the second type of test, cyclic stresses with equal or different amplitudes in two directions were alternately applied with a phase difference of 360 degrees. The results of these tests have shown that the cyclic stress ratios causing 5% simple shear strain in the specimen under multi-directional loadings with two equal amplitudes were on an average 70% as much as the similarly defined cyclic stress ratio under uni-directional loading condition.
