Evaluation of soil damage degree under freeze–thaw cycles through electrical measurements

Abstract

Abstract In permafrost regions, roads and soil slopes experience freeze–thaw cycles annually and the soil characteristics (such as strength and conductivity) change irreversibly. Several studies have been conducted on the evaluation of soil damage using soil mechanics principles and electrical measurements. Owing to the limitations of previous studies, such as low efficiency and the inapplicability of real-time testing for assessing damages, a real-time quantitative test method for assessing the damage degree of layered soil subjected to freeze–thaw cycles based on electrical measurements is proposed. An electrical measurement device was developed for testing the electrical parameters of multilayer soil. Combined with electrical measurements, freeze–thaw cycle tests were performed. The resistivity of each layer of soil under freeze–thaw cycles was determined. Additionally, microstructural parameters of the multilayered soil were determined through computed tomography to investigate the changes in the soil microstructure during freeze–thaw cycles. The porosity and pore distribution characteristics of the multilayered soil under freeze–thaw cycles were obtained using image processing methods, such as median filter and K-means clustering. As the number of freeze–thaw cycles increased, the soil porosity increased, and the pore structure became less complex. Based on the relationship between the soil resistivity and the microstructural parameters, the soil damage mechanism was described, and a damage factor was introduced in developing the model. Furthermore, the dynamic damage process of the multilayered soil under freeze–thaw cycles was evaluated using the damage model, and the settlement was used to verify the results. And the damage model can be applied to evaluate the damage state of soil in permafrost region