Small-strain shear modulus, , is a key evaluation index to study the dynamic characteristics of soil in geotechnical engineering. It is widely adopted to evaluate the stiffness of soft soil in soil dynamic engineering. In this paper, the cyclic triaxial tests and resonance column tests were carried out to explore the variation of of soft clay with respect to various confining stresses, cyclic shear stress ratios, pore pressures, and effective stress paths. Test results indicated that the effective stress decreased gradually with the increase of the cycle shear stress ratio. The failure points were mainly concentrated in a rectangular area, defined by the normalized effective stress from 0.56 to 0.64 and the normalized shear modulus from 0.72 to 0.78. Additionally, a short pause caused a small increase of 1-2% in as well as pore pressure. This study demonstrates that can be effectively used to characterize the failure of saturated soft clay in a more intuitive and convenient way, compared to the commonly used strain failure standards.

中文翻译：

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饱和软粘土小应变剪切模量循环加载试验及其失效机理

小应变剪切模量，，是研究岩土工程土壤的动态特性的一个关键的评价指标。在土动力工程中广泛用于软土刚度的评估。本文通过循环三轴试验和共振柱试验，探讨了软粘土相对于各种围压、循环剪应力比、孔隙压力和有效应力路径。试验结果表明，有效应力随着循环剪应力比的增大而逐渐减小。失效点主要集中在一个矩形区域，由0.56到0.64的归一化有效应力和0.72到0.78的归一化剪切模量定义。此外，短暂的停顿导致孔隙压力和孔隙压力小幅增加 1-2% 。本研究表明，与常用的应变破坏标准相比，可有效地以更直观、更方便的方式表征饱和软粘土的破坏。