Consolidation Analysis of Dredged Slurry Treated by Crosswise-Arranged Prefabricated Horizontal Drains: Analytical and Experimental Insights

Abstract

The use of prefabricated horizontal drains (PHDs) combined with vacuum preloading (VP) has emerged as a popular dredged slurry treatment strategy. However, few theoretical contributions are available to assess its consolidation characteristics in practical engineering design and applications. In this context, an analytical model is proposed to predict the consolidation behavior of the dredged slurry with assistance of PHDs subjected to VP. Initially, an equivalent cylindrical unit cell is established in accordance with the area equivalence principle. Then the governing equation and analytical solution are derived by converting the external loading into the lateral loading acting on the typical unit cell. In the current model, the layered filling process of dredged slurry and the corresponding layered layout patterns of PHDs are comprehensively incorporated. Furthermore, an in-depth assessment is conducted to explore the impacts of several crucial parameters on the consolidation performance. Additionally, a laboratory model experiment is carried out to treat the dredged slurry by a double-layer crosswise layout of PHDs in combination of VP. Thereafter, the accuracy and reasonability of the obtained solution are validated through degradation analysis and experimental data. Based on the parametric analysis and experimental outcomes, compared with prefabricated vertical drains (PVDs), the use of PHDs is observed to facilitate the transmission of vacuum pressure and ensure a more uniform settlement of dredged slurry, thereby ultimately improving dewatering efficiency.