Abstract:Numerous indoor tests and engineering applications have confirmed the superiority of prefabricated horizontal drains(PHDs) combined with vacuum preloading in treating dredged sludge yards. However,existing consolidation theories for PHDs-treated dredged slurry currently lack consideration of well resistance effects. In this study,based on Gibson's large strain consolidation theory,the well resistance effect of PHDs is considered,and the nonlinear compressibility and permeability of dredged sludge are introduced to establish a consolidation model for the treatment of dredged sludge yards by PHDs combined with vacuum preloading. Solutions for the proposed consolidation model are derived and validated through comparative analysis with existing self-weight consolidation models for ideal PHDs configurations and laboratory test results. Furthermore,the influence of well resistance effects on consolidation behavior is systematically investigated. The results indicate that:Well resistance effects decelerate the dissipation rate of excess pore water pressure,consolidation rate,and settlement deformation,though this retardation diminishes progressively with weakening well resistance;The magnitude of well resistance depends on PHDs installation length,permeability coefficient,laying ratio of the PHDs,and the height of the sludge;Optimization of PHDs layout enhances the consolidation efficiency of dredged sludge. Prioritizing PHDs alignment along shorter repository dimensions effectively mitigates well resistance impacts on consolidation processes. When the laying ratio(?) remains below 40%,increasing λ enhances consolidation rates through improved drainage capacity. Beyond this threshold,however,multi-layer PHDs becomes essential to achieve further efficiency gains.