During the last decades, the precast concrete and bored pile foundation system installed to significant toe bearing in dense soils are typically used for high-rise buildings in the Quang Nam province, Vietnam. Because of the anticipated significant costs of this solution, a more economical alternative foundation system was essential, and the alternative of the foundation rested on floating soil-cement columns was proposed for a 5-story hospital building. The soil profile consists of medium dense silty clay into 28 m depth deposited on dense to compact silty sand. Two single columns and one group of 5 columns with open spaces between columns from 30 through 100 mm, 800 mm in diameter, were constructed using the wet deep mixing method into 14 m depth to serve for test and design of building foundation. The head-down tests were performed and the maximum test loads on the single columns and column group were about 400 and 2,000 KN, respectively. The measured maximum movements ranged from about 3.4 through 6.5 mm. The proposed solution saved about 30 % of cost of original designed foundation supported by 300 mm square precast concrete piles driving into 30 m depth. Effectiveness of solution is illustrated and discussed and modeling of soil-cement columns is analyzed by means of the Unified Design Method to response long- term settlements of building.