A Method commonly used to stabilize expansive soils is mixing the soil with foreign materials. The main obstacle raised from soil stabilization in the field is the difficulty in mixing process. This paper presents the strength distribution in soft soil due to the addition of single columns of quicklime and carbide waste- product from gas industry that contains Calcium Oxide (CaO) up to 60%. The results show that the addition of columns filled with carbide waste product and quicklime increase the shear strength of surrounding soil. The spreading of the strength tends to follow a unique pattern, that the increase of soil shear strength at a certain normalized-distance, S (in column diameter D) from the column axis is constant. A significant increase of strength occurs in the area
closer to the column, and it decreases with the distance from the column.