Improving consolidation of dredged slurry by vacuum preloading using PVDs with varying filter pore sizes

Prefabricated vertical drains (PVDs) have been used extensively to accelerate the consolidation rate of dredged slurry. While some fine particles from dredged slurry can easily squeeze through the filter into the drainage channel, many cannot. As such, these soil particles deposit on the filter surface causing partial clogging of the drainage path. Although the pore size of filter is recognized as an important factor that influences PVD clogging, the standards for determining the pore size of the filter are lacking. To this end, the traditional gradient ratio tests with four different filter pore sizes were conducted, and the results show that the permeability of the filter at a given head increases with the increase in the pore size of the filter. To remove the effect of the difference between static hydraulic gradient and vacuum pressure, the vacuum preloading tests with varying pore sizes of filters were further conducted. Through these vacuum preloading tests, the degree of vacuum, settlement, pore-water pressure, water content, vane shear strength, and other parameters of PVDs with various filter pore sizes were obtained, and the optimal pore size of filter was determined.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author