Feasibility of Vacuum Consolidation in Managing Dredged Slurries with Wheat Straw as Drainage Channels

다국어 초록 (Multilingual Abstract)

It is suggested to use wheat straw as both vertical and horizontal drainage materials when using vacuum consolidation method to process dredged slurry in this paper. To verify the feasibility of this proposal, compression and hydrulic conductivity test on wheat straw and vacuum consolidation tests on slurry using wheat straw as drainage materials were conducted. The results show that the compression process of wheat straw is composed of instantaneous settlement and creep. The density of wheat straw changes from 20 kg/m3 to 200 kg/m3 as vertical stress varies from 5 kPa to 100 kPa. The creep rate increases to maximum when vertical stress reaches 60 kPa and then decreases with as vertical stress further increases. The hydrulic conductivity coefficient of wheat straw is changed between 104 cm/s and 101 cm/s, which decreases linearly as density increases in semi-logarithmic coordinates (hydraulic conductivity in log scale). In vacuum consolidation tests, the settlement, water content, and undrained shear strength of slurry proceeded by vacuum consolidation with wheat straw as drainage materials are similar to those obtained by using PVD and sand as drainage materials. All the results obtained by this paper show that it is feasibility to use wheat straw as vertical and horizontal drainage materials in vacuum consolidation.

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