Discrete element method based analysis of soil disturbance induced by different penetration devices

Understanding actual field conditions is important in construction projects, where various in situ devices are used for subsurface characterisation. However, limited research has been conducted on the relative soil disturbance caused by device insertion. This study investigates soil disturbance induced by device penetration using discrete element method-based modelling. Commonly used devices that have different sizes and geometries, including the cone penetrometer, dilatometer blade, and Ko stepped blade, are inserted into model soil specimens, and the stress and strain responses of the soil to assess relative soil–device interactions are quantified. The results show that larger-width devices generate higher stress concentrations and greater permanent strains, while smaller-width devices and geometrical transitions associated with the devices redistribute stress more gradually, reducing overall stress and strain. In addition, geometric transitions are seen to induce closed-loop hysteresis in particle movement, effectively behaving like multi-tip devices. These findings confirm that soil disturbance occurs regardless of device size and shape, emphasising the importance of considering the device geometrical effects in interpreting in situ testing results.