MACRO- AND MICRO-BEHAVIORS OF SOIL WITH SOLUBLE PARTICLES DURING 1D COMPRESSIONAL TESTS USING 3D DEM SIMULATION

Abstract

Micro- and macro-behaviors of soils are significantly affected by soluble particles such as salts. To investigate the macro- and micro-behaviors of soil specimens with soluble particles, this study adopted the discrete element method to model a conventional one- imensional compression test (oedometer) for a sample of 10% salt. Salt particles are created to be softer compared to sand particles. The 3D discrete element method model was validated by laboratory experimental results carried out in a previous study. The oedometer was conducted by applying loads from 5kPa to 640 kPa. Macro- and microbehaviors of the specimen were investigated by observing several parameters, including vertical strain, porosity, vertical and horizontal stress, and contact force during compression. The simulation results showed that the 3D discrete element method model approximately relocated laboratory experimental results, with a high correlation to vertical strain and void ratio. The lateral earth pressure ratio continuously decreased during loading. Moreover, observation of the force chain during loading revealed a rearrangement of soil particles and enhancement of inter-particle
contacts. The macro- and micro-behaviors of soil with soluble particles could be effectively investigated using the 3D discrete element method model. The model provided a reliable framework for capturing the macro- and micro-mechanical properties of granular mixtures with soluble grains under confined compression. However, the dissolution of the sample was not implemented. Future research could focus on the dissolution phenomenon in the 3D discrete element method model to provide a deeper understanding of soluble particles on soil behaviors, particularly under changing environmental conditions.