A simplified single-phase depth-averaged model for rock-ice avalanche movement considering ice melting

This paper considers a simplified single-phase depth-averaged model for simulating rock-ice avalanche movement, which incorporates an energy conservation equation to describe the evolution of mass temperature, accounting for the transition from negative to positive values and vice versa. Additionally, this model introduces a saturation parameter that quantifies the impact of pore water pressure on the normal stress of flow materials. To validate the feasibility of the presented model, two laboratory experiments are simulated. Based on the comparison between numerical results and measured data, this study demonstrates that the presented model captures the transformation of rock-ice avalanches from granular flow to debris flow induced by ice melting during movement and the evolution of associated variables including ice volume fraction and temperature. This study further investigates the impact of factors such as fluid viscosity and melting water on rock-ice avalanche movement through simulation. The findings demonstrate that fluid viscosity has an impact on the morphology of rock-ice avalanches and the rate of ice melting. Consequently, this influence directly affects the movement of rock-ice avalanches. In addition, the cohesive force generated by meltwater impedes the progression of low-speed rock-ice avalanches, particularly those with lower water content. •A depth-averaged single-phase rock-ice avalanche model that considers ice melting and temperature evolution is proposed.•A parameter is introduced to quantify the impact of ice melting on the pore water pressure of flow materials.•Fluid viscosity influences the rate of ice melting, thereby affecting the movement of rock-ice avalanche.•Water cohesive forces hinder the movement of low-speed rock-ice avalanches characterized by lower water content.