Numerical analysis study on determination of unfrozen water saturation curve for sandy soil

The presence of unfrozen water in frozen soils considerably affects the thermal, hydraulic, and mechanical behaviors of the ground. A thorough examination and accurate estimation of the unfrozen-water saturation curve of target soil materials are required to reliably predict the behavior of frozen soils. This study presents a methodology for accurately determining the curve-fitting coefficients included in an empirical model equation. This study differentiates itself from existing research by presenting a method for easily determining the fitting curve coefficient of empirical unfrozen water saturation model through simple freezing experiment data (time-temperature data) and iterative calculation of numerical analysis. An appropriate unfrozen-water saturation curve of sandy soil specimens was obtained by conducting iterative numerical analyses based on indoor experimental data. The reliability of the determined unfrozen-water saturation curve was evaluated by comparing the simulation results for a single freeze-pipe freezing example with an analytical solution.