The clogging-column effect severely impedes the efficiency of vacuum preloading with prefabricated vertical drains (PVDs) in treating ultra-soft dredged slurries. Existing equivalent smear models are useful for overall prediction but generally do not explicitly distinguish the different physical processes in clogging development. In this study, a large-strain radial vertical consolidation model is developed in which the clogging effect has two components: (1) permeability deterioration associated with soil fabric reorganization, described by α, and (2) rapid local densification near the drain under high hydraulic gradients, described by η. The model also considers time-dependent decay of drain discharge capacity through β, together with spatially varying radial permeability. An implicit finite difference scheme solves the governing equations. Parametric analyses indicate that η mainly affects early-stage clogging, α governs the long-term low-permeability state, and β influences drainage efficiency in the middle and late stages. Comparison with a field case in Wenzhou, China shows reasonable agreement with measured settlement. For this case, MAE and RMSE are reduced by 15.5% and 18.5%, respectively, while R2 increases from 0.881 to 0.921. The proposed formulation provides a useful basis for interpreting clogging-affected vacuum consolidation of dredged slurry.
Liang et al. (Mon,) studied this question.