Evaluation and Quality Control of Dry Jet Mixed Clay Soil-Cement Columns by SPT

Dry Jet Mixing (DJM) has been widely used since the 1980’s for stabilization of soft soil. The quality and strength of the DJM columns must be evaluated to confirm success of the stabilization. This paper shows that the Standard Penetration Test (SPT) is a simple and effective method for this task. The strength characteristics along the length of the column are presented and correlations between the SPT blow count and the unconfined compressive strength are developed.