This case study presents the design, operation, and results of a soil improvement project using the vacuum preloading method on the area of 12,0000m2 for Dinh Vu Polyester Plant in Dinh Vu, Haiphong, Vietnam. The effects of soil improvement are demonstrated through the average consolidation settlement of 1.2 m and increases in undrained shear strengths by a factor of two to four or more. The study shows that the vacuum method is an effective tool for the consolidation of very soft, highly compressive clayey soils and loose sandy soils over a large area. This technique is especially feasible in cases where there is a lack of surcharge loading fills, short time schedule of project, extremely low shear strength, soft ground adjacent to critical slopes, feasibility to construction of clay/mixing wall to protect vacuum through sand layers and access to a power supply.
