Factors Affecting Coupled Surcharge–Vacuum Preloading Consolidation with PVDs

This study investigates the influence of various factors that affect the consolidation behavior of soft soil deposits using prefabricated vertical drains with coupled surcharge–vacuum preloading. A proposed mathematical solution incorporates multiple factors related to the multistage time-dependent surcharge application, parabolic permeability and volume compressibility distributions in the smear zone, and time–depth varying well resistance. The proposed solution is confirmed with the existing analytical solutions and two case studies. Finally, parametric studies are conducted to study the behavior of various factors such as volume compressibility ratio, smear zone ratio, drain spacing, smear zone permeability ratio, discharge capacity decay constant, depth-varying discharge capacity factor, initial drain permeability ratio, and vacuum loss along the drain. The findings indicate that the mentioned factors collectively influence the rate and effectiveness of soil consolidation.