ABSTRACT
Tunnel leakage can transport fine particles into tunnels, initiating suffusion. Train vibrations significantly affect the movement of both sand particles and water around the tunnel, but the impact of vibration on suffusion has not been fully understood. In this study, a novel coupled discrete element method (DEM) and pore network method (PNM) approach is developed to simulate element-scale suffusion of gap-graded soils subjected to vibration. The method can reflect the behavior of soil particles and reveal the evolution of fluid at a pore scale. A sample with a frequency of 30 Hz and a displacement amplitude of 0.02 mm is modeled to undergo suffusion. A static model of the same scenario is also simulated for comparison. The results indicate that vibration induces a greater erosion mass during suffusion compared to the static case. Vibration can deteriorate the soil’s erosion resistance by both preventing the formation of new soil arches and destroying existing ones. Moreover, fluid analysis indicates that vibration causes a considerable increase in pore pressure and obstructs fluid flow. The findings from this paper provide a critical understanding of suffusion subjected to vibration loads, helping to reduce the risks of damage caused by suffusion.
