Induced Polarization of Clay Under Freeze-Thaw Cycling and Desiccation Processes: Effect of Surface Cracking Propagation

Abstract

Freeze-thaw cycles and desiccation drastically affect soil surface cracking and shrinkage processes, altering soil pore structures and hydraulic properties. However, studies using geophysical methods to assess how soil crack patterns and shrinkage respond to climate change remain scarce. Induced polarization, a non-intrusive geophysical technique, is highly sensitive to the moisture content and pore structure of the porous media. For the first time, we investigate the effect of soil surface crack patterns on complex conductivity under freeze-thaw cycling and desiccation processes using a new experimental set-up. Results show that Y-junction-dominated crack patterns form on the sample surface after freeze-thaw cycling, and surface cracking network extends along existing cracks until desiccation ceases. Our findings from induced polarization experiments reveal that two components of complex conductivity are linearly sensitive to surface crack ratio and gravimetric water content. Additionally, they both exhibit a similar decay behavior with drying time. In summary, these results indicate that induced polarization provides a preliminary approach for monitoring the surface crack patterns of clayey soils.