Numerical study on clogging of prefabricated vertical drain in slurry under vacuum loading

This paper presents a microscopic numerical study on membrane clogging of prefabricated vertical drain (PVD) installed in slurry when treated by vacuum preloading method. The motions of the slurry particles and the pore fluid are described using discrete element method and computational fluid dynamics method, respectively. The PVD membrane is simulated by the hexagonal packing of spherical particles fixed in space. The clogging processes of the PVD membrane are reproduced for different vacuum pressures. It is observed that a thin and dense soil layer (i.e. the filter layer) forming on top of membrane is responsible for the PVD clogging. A linear relationship between the logarithmic permeability and the void ratio is found for the filter layer, the slope of which agrees with published results based on experiment data.