Reinforcement Effect of Polyacrylamide on Dredger Fill Improved by Vacuum Preloading

Abstract

A series of laboratory tests were carried out to evaluate the effectiveness of polyacrylamide (PAM) on dredger fill combined with the vacuum preloading method. Five groups of vacuum preloading model tests were conducted, and the groups were mixed with 0, 15, 30, 60, or 90 mg/L PAM. The test results indicated that the optimal dosage of PAM is 30mg/L for the Tianjin Binhai dredger fill with a water content of approximately 300%. The optimal dosage of PAM can not only considerably shorten the consolidation time of the dredger fill but can also notably increase the rate of dissipation of excess pore pressure. An approximately 70% increase in the vane shear strength was also observed. Mercury intrusion porosimetry was performed to analyze the pore characteristic parameters of the soil samples after vacuum preloading combined with PAM, and the results revealed that an excessive dosage of PAM can lead to relatively bigger pore diameter in the soil samples.