Economy and environmental safety have recently become very important factors in the construction of soil structures. A combined technology of shallow stabilization and floating-type cement treated columns has an advantage to reduce the construction cost of the soil structure on deep soft soil layers. In this paper, bearing capacity of this type improved ground were investigated. At first, in order to evaluate bearing capacity of this type improved ground, skin friction applied around surface of the floating type column was investigated. Secondly, loading model tests were conducted under the plane strain condition in different improvement conditions to investigate failure tendency of the improved ground. Finally in order to evaluate bearing capacity of this improved ground, equivalent conversion model is proposed with consideration of skin friction. It was confirmed that bearing capacity of the improved ground can be estimated by using this proposed model. By using this model, the embedded depth of an equivalent foundation can be related to the improvement parameters such as improvement ratio and improvement depth.
