Experimental and theoretical study of the shear strength of ice-rock interface

Frost heave failure of fractured rock is an important and challenging problem faced by geotechnical engineering structures in cold regions. The shear strength of the ice-rock interface is a critical parameter in understanding this type of failure. In this study, we conducted shear tests on ice-rock interfaces to examine effects of freezing temperature, normal stress, and interface roughness on the shear strength of the interface. Furthermore, we derived a theoretical model for the shear strength of the ice-rock interface considering these three influencing factors. Comparisons between the theoretical and experimental results confirmed that the shear stress at the ice-rock interface was composed of two components, i.e., the ice-rock particle bonding stress and the frictional stress caused by the rough interface. The freezing temperature mainly affected the bonding stress of ice-rock particles, while the normal stress and the roughness affected the frictional stress. The ice melting happened during the shearing process, leading to the appearance of a second or third peak in the stress-strain curve.