Weathered Red mudstone is widely distributed in Sichuan basin. The compacted weathered red mudstone has been used as subgrade fill materials of high-speed railway in southwestern of China. Dynamic responses of such materials under cyclic loading are critical to long-term stability of subgrade. Shakedown concept is widely employed in characterizing the permanent deformation behavior of soils. According to the evolution of axial strain (Werkmeister’s theory) or unit dissipated energy (Tao’s theory) with loading cycles, the behavior of unbound granular materials can be classified into three categories: plastic shakedown, plastic creep and incremental collapse. However, both theories are more suitable for the unbound granular materials with some limitations when used to separate the plastic creep and incremental collapse behavior. To overcome the limitations of the current theories, 26 cyclic triaxial tests were conducted on a saturated fully weathered red mudstone (SFWRM) to study the evolution of axial strain and unit dissipated energy during cyclic loading. A clear dependency of axial strain, axial strain rate on the unit dissipated energy level under various cyclic stress states were observed. A new criterion which is based on the responses of unit dissipated energy with cyclic stress ratio, was proposed to determine the limit between plastic creep and incremental collapse. Comparing with Werkmeister’s criterion and Tao’s criterion, the proposed criterion showed a better performance in identifying the incremental collapse behavior of the SFWRM.

风化红泥岩在四川盆地广泛分布。压实风化红泥岩已作为西南地区高速铁路的路基填充材料。此类材料在循环荷载下的动态响应对于路基的长期稳定性至关重要。安定概念广泛应用于表征土体的永久变形行为。根据轴向应变（Werkmeister 理论）或单位耗散能（Tao 理论）随加载循环的演变，未结合颗粒材料的行为可分为三类：塑性安定、塑性蠕变和增量塌陷。然而，这两种理论都更适合于未结合的颗粒材料，在用于分离塑性蠕变和增量塌陷行为时存在一些局限性。为了克服现有理论的局限性，对饱和全风化红泥岩（SFWRM）进行了26次循环三轴试验，研究循环加载过程中轴向应变和单位耗散能的演变。在各种循环应力状态下，观察到轴向应变、轴向应变率对单位耗散能水平的明显依赖性。提出了一种基于单位耗散能对循环应力比的响应的新准则来确定塑性蠕变和增量塌陷之间的极限。与Werkmeister准则和Tao准则相比，所提出的准则在识别SFWRM增量倒塌行为方面表现出更好的性能。对饱和全风化红泥岩 (SFWRM) 进行了 26 次循环三轴试验，以研究循环加载过程中轴向应变和单位耗散能的演变。在各种循环应力状态下，观察到轴向应变、轴向应变率对单位耗散能水平的明显依赖性。提出了一种基于单位耗散能对循环应力比的响应的新准则来确定塑性蠕变和增量塌陷之间的极限。与Werkmeister准则和Tao准则相比，所提出的准则在识别SFWRM增量倒塌行为方面表现出更好的性能。对饱和全风化红泥岩 (SFWRM) 进行了 26 次循环三轴试验，以研究循环加载过程中轴向应变和单位耗散能的演变。在各种循环应力状态下，观察到轴向应变、轴向应变率对单位耗散能水平的明显依赖性。提出了一种基于单位耗散能对循环应力比的响应的新准则来确定塑性蠕变和增量塌陷之间的极限。与Werkmeister准则和Tao准则相比，所提出的准则在识别SFWRM增量倒塌行为方面表现出更好的性能。观察了不同循环应力状态下单位耗散能水平的轴向应变率。提出了一种基于单位耗散能对循环应力比的响应的新准则来确定塑性蠕变和增量塌陷之间的极限。与Werkmeister准则和Tao准则相比，所提出的准则在识别SFWRM增量倒塌行为方面表现出更好的性能。观察了不同循环应力状态下单位耗散能水平的轴向应变率。提出了一种基于单位耗散能对循环应力比的响应的新准则来确定塑性蠕变和增量塌陷之间的极限。与Werkmeister准则和Tao准则相比，所提出的准则在识别SFWRM增量倒塌行为方面表现出更好的性能。