Vibro Stone Columns
In granular soils, the Stone Columns increase the density of the surrounding soils providing liquefaction mitigation, improved bearing capabilities and reduced settlement. In fine grained soils Stone Columns are installed to increase the time rate of settlement, reduce the magnitude of settlement and improve load bearing characteristics.
Vibro Stone Columns are formed by inserting a vibratory probe into the ground to create a void, backfilling the void with stone in approximately 2-foot-thick lifts to the ground surface. Each lift is compacted by inserting the vibratory probe into the stone. The procedure is repeated until adequate stone compaction and column size has been achieved.
Where the Stone Columns are relatively shallow, and the in-situ soils are not extremely soft, a stable void is created and the stone backfill can be added by partially or fully removing the probe. This is known as the top-feed method. For deeper applications, and when the soils are prone to collapsing, the stone is introduced via a side-feeder tube without removing the probe. This is known as the bottom-feed method
Advantages of Vibro Stone Columns:
- Increases bearing capacity
- Reduces total and differential settlement
- Expedites consolidation settlement
- Mitigates the risk of liquefaction
