Vibro Compaction (VC) 1
Vibro compaction is a highly effective ground improvement technique that utilizes a specialized downhole vibrator to densify and strengthen loose, clean, and granular soils. This process involves the strategic placement of the vibrator at predetermined intervals, where it creates strong vertical vibrations that compact the soil particles and remove any trapped air or water pockets. The result is a more stable and durable foundation better equipped to support heavy loads and resist future settlement.
Common uses
- Reduce foundation settlement
- Increase bearing capacity, allowing reduction in footing size
- Increasing stiffness
- Increasing shear strength
- Reduce permeability
- Mitigate liquefaction potential under a seismic event
- Prevent earthquake-induced lateral spreading
- Increase slope stability
- Permit construction infills
Process
Ground compaction is a crucial process in engineering, mainly when dealing with granular, cohesion-less soils that lie deep beneath the ground surface. Fortunately, with modern technology, ground compaction can be done without excavation. Keller-made vibrators are a testament to the advancements in this field, and continuous research and development are still being carried out to develop vibrators that can compact soils with wide grids and depths of up to 50m.
The process involves lowering a vibrator from a crane into the ground, with water jetting providing the necessary penetration. The vibrator’s energy reduces the intergranular forces between soil particles, leading to denser soil as the vibrator is raised in lifts. To compensate for any decrease in soil volumes, sand backfill is poured in from the ground level. The process is repeated until the vibrator is gradually removed and the soil has built up to ground level.
Vibro rigs can be fully instrumented with an onboard data acquisition system, which enables real-time data recording and display of production data such as amperage and lift rate on an in-cab monitor.
Advantages
- A versatile ground-improvement method that can be adjusted to a wide variety of soil conditions and foundation requirements
- Offers an economical solution for ground improvement
- Can be carried out to almost any depth
- Relatively quick execution so subsequent structural works can follow very quickly
- Environmentally friendly as uses natural and in situ materials
- Negligible noise levels during production
- Maintains original site elevation where backfill is used
