Investigating soil fluidisation using a coupled TFM-KTGF model

A computational fluid dynamics model was used to study localised soil fluidisation around leaking water pipes using leakage rate and crack width, soil particle diameter and its peak friction angle, and soil bed thickness as the five variables. The problem was investigated using the dimensions of the fluidised cavity and the velocity of the solid phase as the output. The effect of viscous and frictional model was assessed using a two-fluid model coupled with the kinetic theory of granular flow to get insight of the continuum approach. The effect of frictional viscosity model becomes pronounced for higher leakage rates. The dimensions of the cavity were equally sensitive to the particle size. The cavity remained hidden within the soil-bed, if the backfill consisted of only coarse particles. The effects of bed thickness and friction angle were relatively insignificant compared to the other investigated parameters. For the same leakage rate and bed height, the cavity height was higher for narrow cracks.