Rapid Treatment of Mud Slurry Using a Vacuum-Assisted PHD and Solidification Combined Method

Abstract

Mud slurries are characterized by high water content and low strength; therefore, treatment (which included volume reduction and strength improvement in this study) was required before they could be transported, handled, and reused more easily. This study presented a method that combined prefabricated horizontal drains, vacuum preloading, and solidification (PHDVPS) for the rapid treatment of mud slurry with high water content. The performance of the PHDVPS method was experimentally investigated and compared with traditional methods that used only vacuum preloading or only solidification. Settlement and the mass of the discharged water (mvw) were monitored in model tests to investigate the dewatering efficiency (i.e., volume reduction). Then, unconfined compressive strength (UCS), permeability, X-ray diffraction (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) tests were conducted to investigate the mechanical, hydraulic, and microstructural properties of the PHDVPS-treated soils. The results indicated that the PHDVPS method significantly outperformed the traditional vacuum preloading and direct solidification methods for volume reduction and strength improvement. In addition, parametric studies indicated that the initial water content (wo) of mud slurry, cement content (Aw), duration of vacuum preloading (tp), and magnitude of vacuum pressure (σvp) had a significant influence on the performance of the PHDVPS method.