A micro frost heave model for porous rock considering pore characteristics and water saturation

Frost heave of rocks is a significant challenge in cold regions, posing threats to geotechnical engineering and causing geo-disasters. This study presented a novel micro frost heave model based on Discontinuous Deformation Analysis (DDA) to investigate the mechanism of frost damage in porous rock, with a specific focus on the coupling effect of pore characteristics and water saturation. First, pore ice was divided into three categories based on capillary mechanics, and they were treated differently in DDA according to their characteristics. Then, the developed model was validated by comparing numerical simulation with the physical experimental results of the parallel-sided slot model. Subsequently, simulations were conducted to analyze frost heave strain, pore damage, and the uniaxial compressive strength (UCS) of the frozen sandstone samples at varying water saturations. Finally, the microscopic mechanisms underlying UCS characteristics, such as the peak strength and the critical saturation, were discussed in detail. This research offered a novel and simple model for investigating the micro-mechanisms of the mechanical behavior of frozen rock.