Investigating the influence of excitation force on compaction behavior of gravel in granular blends through DEM simulation

Abstract

Abstract During the construction of subgrades, the compaction of granular blends is typically achieved through vibrational techniques at varying the frequencies and excitation forces. This study investigates the impact of excitation forces, within the range of 300-600 kPa, on subgrade compaction by employing the discrete element method (DEM). Calibration tests were conducted to establish the contact parameters for the DEM models, and their reliability was verified via vibration compaction tests. The research further explores the evolution of settlement, particle motion, and contact interactions at both macroscopic and mesoscopic levels as influenced by the excitation forces. Furthermore, the influence of excitation force on the stability of skeleton frameworks was analyzed. The results indicated that the number of contacts in the final state increased consistently with the excitation force, leading to a more uniform distribution. This change contributes to a time-dependent stability within the skeleton framework, which effectively limits the movement of fine particles in the final stages and diminishes the sliding between the coarse particles. Conversely, in the initial phases, a rise in excitation force increases the stress concentration between the contacts, which increases the sliding damage to the skeleton frameworks and leads to greater compaction deformation.