Bulk Compression of Dredged Soils by Vacuum Consolidation Method Using Horizontal Drains

Abstract

Two landfill sites were constructed on shore to dispose of dredged soil, and dredged soil was reclaimed after the placement of horizontal drains. In this manner, bulk compression of the soil has been achieved by application of vacuum consolidation method. The horizontal drain was a plastic board drain (PBD) with a width of 100 mm, a thickness of 10 mm, and a length of 117 to 171 m. The PBDs were set at both the bottom and the intermediate height of the landfill sites with a horizontal spacing of 0.8 m, and were completely overlaid with the dredged soil. By alternately placing the drain material and disposing of dredged soil at two landfill sites and applying negative pressure continuously to the sedimentary soil, it was possible to deposit an amount of sedimentary soil that corresponds to about 1.1 times the disposable volume at the landfill sites. This paper outlines the implemented construction and presents various measurement results and a settlement analysis.