In order to examine the applicability of the single-sided shear test, this study compared the test results with the results of the triaxial test using the undisturbed Pleistocene clay sample collected from a depth of 50 to 120m, and obtained the following conclusions. .
1) As a result of obtaining the undrained shear strength of the Pleistocene clay soil by the recompression method, the undrained shear strength at a strain rate of 1.25%/min is equivalent to the strength of the triaxial test result (triaxial compression) at a strain rate of 0.1%/min It was about 95% of the average of strength and triaxial tensile strength). Considering the strain rate effect, the unfolded shear strength was less than 90% of the triaxial strength. Therefore, the single-sided shear strength was on the safer side than the triaxial strength.
2) The relationship between the apparent modulus of rigidity G50 obtained from the one-sided shear test and the deformation modulus E50 obtained from the triaxial compression test and triaxial extension test is expressed by the following equation. G50 = 0.26 E50 If Poisson's ratio is 0.5, G50 = 0.33 E50, but the reason why the obtained modulus of rigidity is smaller than this is thought to be that the strain corresponding to G50 is larger than the strain caused by E50 and is due to the strain dependence of the elastic modulus. will be
3) The modulus of rigidity is approximately 100 times the shear strength, and this relationship agrees with the data of other marine clays.
4) Since the results obtained in the direct shear test are almost as accurate as the results of the triaxial test, it is considered that the direct shear test can be used as a practical strength evaluation method for Pleistocene clay.