LAOLUE CHERXIONG

Verification of material combinations in transparent ground experiments

Yutaka Fukumoto

Internal erosion is a phenomenon in which soil particles inside a soil structure are washed away in various ways with osmotic flow by osmotic flow. However, since the internal erosion phenomenon occurs inside the ground, it is not possible to directly observe the damage situation. So far, research on internal erosion of the ground has included visualizing the internal osmotic flow that cannot be directly observed using acrylic spheres and silicon oil as materials, and grasping the characteristics of the osmotic flow. However, silicone oil is more viscous than water, so it is necessary to conduct experiments that are close to actual phenomena. Therefore, in this experiment, I used transparent soil (refractive index matching method) to visualize the infiltration flow of ground erosion using hydrogel spheres and water as materials by preventing the reflection of light by bringing the refractive index of the object and the refractive index of the liquid in which the object is immersed close to each other. Focusing on the degree of curvature T and the Reynolds number of osmotic flow, which indicate the characteristics of porous materials, I examined the combination of materials that are closer to the actual phenomenon through simple model experiments. In addition, the purpose is to examine the transparency of the material in order to observe the individual to be newly stirred.
As a result of the experiment, I conducted a transparent ground experiment using water and hydrogel spheres in the osmotic flow ground experiment, focusing on the hydraulic bending degree of infiltration in the gaps, and examined the accuracy of the combination of materials, and measured the condition of a large Reynolds number. Since hydrogel spheres are very soft and easily deformed, it was confirmed that the accuracy of observation and analysis was reduced by filling the gaps between the particles. In the stirring experiment, the relationship between P40 and the refractive index was confirmed by mixing the liquid paraffins "P40 and P55" used in the stirring experiment, and it was possible to investigate the combination of quartz glass and fluid paraffin to find the highest transparency in the transparent ground experiment.
As a future prospect, in the osmotic flow ground experiment, the results of the experimental accuracy were reduced because the hydrogel spheres are soft and easily deformed. Therefore, experiments can be performed using a larger particle size of a hydrogel sphere, and the accuracy of the experiment can be improved. Since only one camera was used, the observation was conducted in two dimensions, but by using two cameras, the observation was performed in three dimensions. In the stirring experiment, it was confirmed that a large vector was concentrated on the lower side of the analysis image, but there was a part of the upper vector that could not be confirmed to have a large change. Therefore, I will find the method so that I can understand the change in the vector at the top.