Sensitivity analysis of the frozen soil nonlinear latent heat and its precise transformation method

Abstract

Latent heat of soil water phase transition is an important parameter affecting the prediction of the temperature field in a frozen soil. With the non-linear change of unfrozen water content in freezing soil, the latent heat appears nonlinearity in a frozen soil. To evaluate the influence of the estimation of phase quantity and phase change interval on the formation of the temperature field in a frozen soil, the thermal parameters at different temperatures are measured, and a soil freezing model test is carried out. Meanwhile, based on the evolutionary trend of the unfrozen water content, a precise method of transforming the latent heat of phase change into specific heat, and a segment processing method of latent heat in a frozen soil is proposed. And these methods are used in the ABAQUS to simulate the temperature of the soil freezing model. The sensitivity of the estimation of phase quantity and phase change interval on the formation of the temperature field in a frozen soil is analyzed based on the numerical calculation values and model test values. The results show that, the estimation accuracy of phase change interval greatly affects the prediction accuracy of the temperature field in the warm temperature stage, and the method of transforming latent heat into apparent specific heat can improve the prediction accuracy of the temperature field.