Effect of Temperature, Stress, and Ice Content on the Creep Behavior of Glacial Till–Ice Mixtures

Abstract

Numerous rock glaciers have formed in the cryosphere, such as on the Tibetan Plateau, and have resulted in frequent geohazards due to increased global warming. Active rock glaciers contain large amounts of glacial till–ice mixtures (GIMs), and understanding the creep behavior of GIMs under varying temperature and stress conditions is essential for mitigating rock-glacier-related hazards. To investigate this behavior, a series of triaxial creep tests was performed under two different temperature–stress paths. The results indicate that temperature, stress level, and ice content have a coupled effect on the creep behavior of GIMs and that the tertiary creep stage was observed exclusively in GIMs with low ice contents. A reduction in confining pressure significantly decreased the long-term strength of low-ice-content GIMs, whereas its influence on high-ice-content GIMs was limited. As ice content and temperature increase, the long-term strength of GIMs decreases significantly. Moreover, this study demonstrates, for the first time, that the minimum creep strain rate is independent of temperature history. These conclusions can be potentially applied to evaluate the long-term deformation and stability of rock glaciers.