Injection of granular material - Visualization of stress and grain flow
Some civil engineering projects require the injection of granular matter such as sand into the ground. However, granular matter resists pumping through tubes and thus it is difficult to inject such matter into the ground. With the help of several methods forces and movements of grains were visualized. Force chains and arches in a two dimensional granular matter model were visualized with polarized light and photo-elastic material. The movement of sand grains was visualized on a glass plate in a half-space ground model. With the particle image velocimetry (PIV) method the vector field of the movement and the field of the resulting shear rate were assessed. In this way a new method for the injection of granular material, such as, sand into the ground was devised. The method appears to be applicable to lift a building to counter subsidence.
force chains piv subsidence injection of sand granular matter flow