Influence of particle shape on K₀ consolidation characteristics of coarse-grained soils via DEM

The K₀ value is crucial for calculating the bearing capacity of foundations, the stability of slopes, and the earth pressure exerted by retaining walls. The particles in coarse-grained soil often have irregular shapes. To study the influence of particle shape on the K₀ consolidation characteristics of coarse-grained soil, we used a discrete element method to generate five different particle cluster shapes and determine their shape parameters. Using the same particle size, we produced an initial state with the same method. Finally, we performed the K₀ consolidation test to explore the impact of particle shape on the K₀ consolidation characteristics and underlying mechanisms of coarse-grained soil. A comprehensive analysis was conducted on the impact of particle shape and the mechanisms involved. The results show that: (1) The K₀ values of specimens with different shapes decrease as normal stress increases. The K₀ value is positively correlated with the shape parameter of the particles; more regular particles (with a shape parameter closer to 1) have higher K₀ values. Therefore, considering particle shape in engineering design is important; (2) The K₀ value is related to the coordination number (CN) of the particles. More irregular particle shapes lead to higher CN values and lower K₀ values. (3) The K₀ value is connected to the average contact force (MF) and the ratio of strong chains to specimen SP. Irregular particle shapes reduce the ratio of strong chains and the average force, both influencing the K₀ consolidation characteristics of coarsegrained soils. Such irregularities decrease the average force, affecting the K₀ value. These findings can provide a theoretical basis for evaluating the K₀ value in the field, helping to avoid over- or under-design and ensuring project safety and economy.