- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 11 May 2017
Vibro-replacement is a ground improvement technique that can be used to transfer structural loads to suitable levels in poor ground conditions. Another term that can be used for this technique is vibro stone columns (VSC).
The effect of vibration consolidates and strengthens the ground, helping to stabilise granular soils that would otherwise be unsuitable for construction.
It can be a cost-effective alternate method to piled foundations and grouting that can be used for structures such as buildings, embankments, dams, tanks and towers. However, the site must be large enough to accommodate and justify the plant that is required.
The amount of stone fill material must be carefully calculated to ensure that the process does not become uneconomical compared with conventional piles which also have the advantage of having higher bearing capacities.
Another similar method is vibro-compaction.
Vibro-replacement works by using a crane-suspended downhole vibrator to construct stone columns through weak soils, improving their load-bearing and settlement capacities. The vibrator is usually up to 4 metres long, although sometimes it may be necessary, if strata are particularly dense, to pre-drill down to the design depth. There are two processes that can be used:
 Dry process
Weak soil is penetrated to the desired depth and stone used to fill the cavity through a feed pipe attached to the vibrator. The vibrator is then used to compact the stone and ensure it interlocks tightly with the surrounding ground. Successive charges of stone are added and compacted to form a column that is built up to ground level.
 Wet process
Weak soil is penetrated to the design depth by means of the vibrations as well as water jetting from the vibrator’s tip. The stone backfill is then inserted as the vibrator is removed and then used to compact the stone. A water supply of 10,000-12,000 litres per rig hour is usually required for this method.
Both processes can be aided by computers on-board the rigs that monitor specific parameters, allowing operators to respond quickly to any deviations that may occur.
 Related articles on Designing Buildings Wiki
- Driven piles.
- Geothermal pile foundations.
- Grouting in civil engineering.
- Pile foundations.
- Retaining walls.
- Screw piles.
 External references
- Hayward Baker – Vibro-replacement techniques
- ‘Introduction to Civil Engineering Construction’ (3rd ed.),HOLMES, R. (1995), The College of Estate Management
Featured articles and news
Which room is the most fun to design? Find out the 'Grand Designs' presenter's unusual choice in our interview.
Full suite of speakers are announced for this year's BSRIA Briefing event.
Book your place for the Architectural Technology Awards 2018.
There are many ways of classifying types of building. Have a look at our range of building articles.
BSRIA have launched the 'major update' of the go-to design framework guide for building services.
How to get results with building life cycle assessment.
Government publishes a prospectus inviting proposals for new 'garden communities'.
The Morandi motorway bridge in Genoa collapses during rainstorm while undergoing maintenance works.
'Developed design' is a phrase coined by the RIBA for their 2013 Plan of Work. But what does it actually mean?
New green paper published aiming to rebalance the relationship between landlords and residents and tackle stigma.
RIBA calls for a comprehensive ban on combustible materials.