Experimental investigations on the mechanical behaviour of glacial tills and ice mixtures

Glacial tills and ice mixtures (GIMs) are widely distributed in alpine mountain areas, and the mechanical behaviour of GIMs is strongly related to rock glacier-related hazards. In this study, GIMs with different ice contents were divided into three types on the basis of CT scanning tests, and a wide range of ice contents was used to conduct a series of triaxial compression tests. In addition to the stress–strain–volume relationships presented, several indices related to strength and deformation behaviours, as well as the effects of temperature and confining pressure, were investigated. The results indicate that, generally, an increase in the ice content causes a decrease in strength. However, this phenomenon differs at temperatures near 0 °C, where the strength decreases before increasing with increasing ice content. The confining pressure has different influences on the brittleness at different ice contents. As the ice content increases, the effect of temperature on the brittleness decreases. Furthermore, the maximum dilatancy ratio tends to be independent of the confining pressure and temperature for GIMs with high ice contents. The conclusions of this study can be used to understand the mechanical behaviour of GIMs and are potentially useful for predicting rock glacier-related geohazards.