Discrete Element Analysis of Reduced Bearing Capacity under Ground Vibration

Abstract

Numerous missions have targeted planetary bodies, highlighting the need for advanced mobility technologies that enable exploration beyond the surface. Vibration-driven underground locomotion is a promising approach because vibration can alter soil behavior and reduce resistance to movement. However, the particle-scale mechanisms responsible for this reduction remain unclear, limiting the development of efficient vibration-based locomotion systems. In this study, particle-based numerical simulations and experiments were used to investigate how vibration reduces the resistance acting on an object moving through granular ground. A numerical model was developed to reproduce rod-dragging experiments conducted with a vibration amplitude of 0.25 mm at frequencies of 30 Hz and 50 Hz. The simulated resistance showed good agreement with the experimental results under the no-vibration and 50 Hz conditions, with errors within 2%. The results demonstrated that vibration reduced the resistance acting on the moving rod compared with the no-vibration condition. Particle-scale analysis further revealed that vibration generated high-velocity particle regions ahead of the rod and promoted particle rearrangement around it. These effects suppressed particle accumulation in front of the rod, thereby reducing resistance to motion. The findings clarify the relationship between vibration-induced particle flow and reduced soil resistance, providing a physical basis for the development of vibration-driven underground locomotion systems. Beyond planetary exploration, the numerical modeling of vibration-induced changes in granular ground may also contribute to broader engineering applications, including civil engineering problems involving vibrated granular materials.

Received: 27 March 2026 | Revised: 27 June 2026 | Accepted: 2 September 2026

Conflicts of Interest

The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

Data are available from the corresponding author upon reasonable request.

Author Contribution Statement

Tomohiro Watanabe: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Writing – original draft, Writing – review & editing, Visualization, Project administration, Funding acquisition. Dai Watanabe: Conceptualization, Resources, Writing – review & editing. Kojiro Iizuka: Conceptualization, Resources, Writing – review & editing, Supervision.