The aim of this note is to reexamine the stress and strain conditions of cyclic triaxial and cyclic simple shear tests for evaluating the liquefaction strength of natural sandy soil. The conventional method of determining the liquefaction strength relies on the shear stress components. However, the use of stress invariants eliminates the need to specify the stress components, thereby making it a more rational approach for determining the liquefaction strength. A comparison of the results using the conventional stress ratio and the stress invariant ratio is done in this study. A strong correlation is seen between the liquefaction strengths obtained from the triaxial and the simple shear tests when using the stress invariant ratio. Despite this strong correlation, large scattering still remains due to the effects of the soil fabric of the natural sandy soil. A torsional hollow cylindrical device is used here to perform simple shear tests on undisturbed natural sandy soil.

本说明的目的是重新检查循环三轴和循环简单剪切试验的应力和应变条件，以评估天然砂土的液化强度。确定液化强度的传统方法依赖于剪切应力分量。然而，使用应力不变量消除了指定应力分量的需要，从而使其成为确定液化强度的更合理的方法。本研究对传统应力比和应力不变比的结果进行了比较。当使用应力不变比时，从三轴试验和简单剪切试验获得的液化强度之间存在很强的相关性。尽管存在这种很强的相关性，由于天然沙土的土壤结构的影响，仍然存在大量的散射。这里使用扭转空心圆柱装置对原状天然沙土进行简单的剪切试验。