Study on characteristic of fluid soil in the chamber of EPB shield

The visualization system has been developed to control the fluidity of excavated soil in chamber EPB shield real time during advance. For further improvement system, agitation tests fluid sand mixing with CMC aqueous solution as a thickening material or rheological form enhance have carried out clarify its flow property. It was confirmed by that agitating flapper torque decreased increase number rotations. is assumed above-mentioned phenomenon caused friction in-between particles. Therefore, property not exactly same general viscous materials. is, however, useful evaluate this numerical formula using power-law model for which shear stress decreases shearing deformation rate, and apply analysis, if analysis able simulates behavior high accuracy. As result tests, formulas based on applied negative value power index proposed sand.