*5.1. Visualization for Performance of Discharging Surplus Soil by Velocity Display*

The conditions during the discharge of surplus soil in the RS-DMM construction were evaluated by the distribution of the moving velocity of the particles. Figure 7 shows the analysis cross section at the stage (at 70 s) when the penetration and stirring are completed and the static stirring is performed at the bottom. Focusing on the moving velocity of the particles around the rod in the figure (the area surrounded by the black rectangle), in the case of using the stirring wing of the NT, many particles with a moving velocity close to 0 m/s are distributed. On the other hand, in the case of using the stirring wing of the DRT, there are many particles with a moving velocity of 0.3 m/s or more. Due to the effect of the spiral rod attached to the stirring wing of the DRT, particles are forcibly moved upward, and the surplus soil is discharged. Therefore, construction using the stirring wing of the DRT in the RS-DMM is found to be effective for suppressing displacement.
