Sand column is one of the soft ground improvement methods. It is made up of well compacted sand pile, it is used for enhance the load capacity of soft clay soils, reduce the settlement and accelerate the consolidation process of the native soft soil surrounding it, also the sand column is used to minimize the likelihood of liquefaction when installed in loose sand soils.
This research deals with the evaluation of a mathematical equation depending on the results obtain from series of triaxial test in order to calculate the bearing capacity of sand column which inserted in soft clay soil and for two different cases (floating case condition and other is when the sand column is resting on a firm base).
The results indicate that the calculation of the shaft resistance for sand column mainly depends on the clay medium properties, while the calculation of the end bearing depends on the sand property (depending on the mode of failure for the sand column, which was observed). Another group of mathematical relations was suggested to calculate the load capacity of sand column inserted in soft clay for two area replacement ratios (11% and 6%) and depending on the confining pressures considered (100-400) kPa, and for two cases, the first is when the sand column in the floating case condition and other is when the sand column is resting on a firm base.