Assessment of Vacuum Preloading of Soft Sediment Applied to Various Drainage Schemes

The effectiveness of incorporating vacuum preloading with various drainage schemes in ultra-soft soil has been assessed by in-situ testing for a reclamation project in Wenzhou, China. The test region was divided into four test plots, with a different testing program in each region that examined distinct drainage paths beneath the soil layer. The field monitoring results identified changes in deformation, stress, and water level with time. The results of the indoor soil tests indicate a substantial reduction in water content and an increase in dry density and undrained shear strength in all four test regimes. Comparisons of the four tests allow us to conclude that vacuum preloading combined with electrodes that are close to prefabricated vertical drains, the method followed in test region 1, works best. The application of test region 1 conditions over the large pretreated area of a reclamation project revealed that the rate of settlement was increased by 60 % and the period of construction was reduced by 8 months.