Discrete Element Method Study on Effect of Shear-Induced Anisotropy on Thermal Conductivity of Granular Soils

In this study, a simple idealization of heat transfer by conduction at the interparticle contacts is utilized for the evaluation of thermal conductivity of granular soils when subjected to external loading conditions. Discrete element method simulations employing this idealization were performed to examine the impact of loading the soil in a consolidated drained triaxial test environment on soil thermal conductivity. Results of conducted simulations show that shear-induced anisotropy results in an anisotropic thermal conductivity tensor. The results also indicate that contact density affects the average thermal conductivity of granular materials. The larger the average number of contacts per particle, or the coordination number, the larger the thermal conductivity. During shearing, the coordination number tends to decrease, resulting in a reduction in soil thermal conductivity with dense soils, showing a larger decrease in thermal conductivity upon shearing. (C) 2013 American Society of Civil Engineers.