Development of an experimental imaging system for the micro-scale study of seepage-induced granular particle mobilization

This paper presents the results of the development and initial testing of an experimental micro-scale particle-mobilization imaging apparatus. The system consisted of three fundamental components: a system to induce seepage, a flow cell to house the porous media specimen, and an imaging system to visually capture the process of seepage-induced mobilization of individual granular particles. The imaging equipment consisted of two components: (1) a high-resolution, high-speed camera capable of capturing up to 1273 frames per second and (2) a high-magnification lens. The flow cell that housed the soil underwent four versions of improvements, with the most recent design allowing for the particle detachment process to be clearly captured by the imaging system. Fine silica sand was used to create the test specimens. The system proved to be capable of capturing the details of seepage-induced detachment of individual particles and will be used for future investigations aimed at accomplishing two primary objectives: (1) quantification of the forces leading to particle detachment and (2) relation of these mobilizing forces to the characteristics of permeating fluids and hydraulic conditions.