stone column is one of the soil stabilizing methods that is used to increase shear strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. The columns consist of compacted gravel or crushed stone arranged by a vibrator.
Stone columns or aggregate piers are an array of crushed stone pillars placed with a vibrating tool into the soil below a proposed structure. Stone columns are made across the area to be improved in a triangular or rectangular grid pattern. The stone columns derive their load capacity from the confinement offered by the surrounding soil.
Stone columns are constructed using specialist equipment. The construction uses an excavator with a vibrating probe to feed stone into the ground, forming a vertical column of stone. Some stone column rigs feed stone into the ground through the vibrating probe, exiting at the bottom, and other rigs require the stone to be fed in from the ground surface down the vertical hole in the ground. Both types use a vibrating probe that densities the surrounding soils to help feed the stone into the ground.