Abstract: This paper presents a successful vacuum preloading on dredged soils without sand blanket project. After 90 days of vacuum preloading, both physical and mechanical properties of the soft soils demonstrated improvements. The soil strength also increased, as examined by both the static plate loading tests as well as the vane shear tests. The bearing resistance of the surface soil reached the design required value of 50 kPa. The bearing resistance determination combined different industrial standards and summarized the design criteria for the bearing resistance for dredged soils. For surface soil within 1.5 meters below the ground, the 50 kPa requirement can be estimated with moisture content of the soil. If the moisture content of the soil is smaller than 57.8%, the bearing resistance of the ground is greater than 50 kPa, whereas, the bearing resistance of the soil is greater than 40 kPa if the moisture content of the soil is less than 62.5%.

Key words: Dredged Soils, Vacuum Preloading, Verification Tests, Improvement Results, Bearing Resistance of Soils