Consolidation of slurry treated by PHDs-VP incorporating development process of clogged zone

Abstract

The prefabricated horizontal drains combined with vacuum preloading (PHDs-VP) method exhibits significant benefits in dredged slurry treatment. This study introduces an analytical model of slurry consolidation treated by PHDs-VP. In this model, the PHD is treated as a permeable boundary with a vacuum pressure. The governing equations are established by dividing the analytical unit into normal zone and clogged zone, and by incorporating the development process of the clogged zone. Numerical solutions are obtained utilizing the finite difference method. The accuracy and reliability of the solutions are validated through both degradation analysis and experimental verification. Furthermore, a parametrical analysis is conducted to investigate the influence of several key parameters on consolidation behavior. The results indicate that the clogging effect significantly retards the consolidation process, with a lower permeability coefficient or a greater thickness of the clogged zone resulting in a more pronounced reduction in the consolidation rate. Additionally, the consolidation rate decreases with the accelerated development of the clogged zone, and this effect becomes more pronounced with denser PHDs layout.