Vibro stone column

Vibro replacement stone columns are a ground improvement technique to improve the load bearing capacity and reduce the settlement of the soil. On many occasions, it is noted that the local soil is, by nature, unable to bear the proposed structure, so the use of ground improvement techniques may be necessary. Use of stone columns is one such technique. The stone column consists of crushed coarse aggregates of various sizes. The ratio in which the stones of different sizes will be mixed is decided by design criteria.

The aforementioned crushed aggregates in the definite proportion are to be placed into the soil at regular intervals throughout the area of the land where the soil bearing capacity is to be improved. This is done either by using the dry or the wet top feed vibrators which are forced into the ground. The aggregates are then allowed to take the place of the displaced soil which exerts a pressure on the surrounding soil, hence helping to improve the soil's load-bearing capacity.

The vibrating pore breaks down the pores of the surrounding soil, thereby densifying the soil. The crushed aggregates or the gravel that is poured in takes the place of the soil and keeps up the pressure on the soil that was created by the vibrating probe.

These columns are made across the area to be built on in a grid pattern at regular intervals.

References

Article at the Soil Liquefaction web site of the University of Washington