Load Transfer Mechanism of Group of Floating Soil-Cement Column In mproving Soft Ground

Soil-cement column by deep mixing method as ground improvement was proven effective enough to improve soft soil for foundation of structure, earthen embankment, rafts foundation, and where a relatively large settlement is permissible. However, the load transfer mechanisms between the column and the surrounding soil especially for a group of floating soil cement column is still lack of investigation. This paper presents the stress sharing mechanism under rigid footing supported by a group of floating cement column. This paper focuses on the development of stress distribution and stress concentration ratio, η under instant loading. Thus, a series of laboratory experiments were carried out to measure the stress of the column and the surrounding soil. For comparison, finite element analysis was performed using PLAXIS 3D with Undrained analysis. Generally, it was found that a group of floating soil cement column shared 1 to 4 times more loads than the surrounding soil with the range of applied stress of 14 kPa to 20 kPa. Moreover, in all cases, it can be seen that the stress measured in lab and predicted by PLAXIS 3D showed a small discrepancy between the results. In addition, good interpretation and understanding on the load transfer between the column and the surrounding soil was obtained by the used of finite element analysis.