An alternative method to building stone columns by bottom-feed vibroflot is driving a capped casing into the soil, filling it with gravel and extracting the casing leaving the cap and a stone column behind. This method is also ‘dry’ and has high production rates, good verticality and easily certifiable column width and volume. This method is preferred for stone columns greater than 30 meters in depth, as the vibroflot units with followers will be more unwieldy to use for these depths then a steel casing. The ring vibrator is an excellent choice where height restrictions are enforced, such as in the vicinity of airport runways.

The recommended set-up for larger diameter, longer stone columns, is to use a ring vibrator and specialized piling rig like the PVE 90DR. The ring vibrator is attached to the piling rigs leader, the casing runs through the middle of the hammer leaving the top of the casing open for easy gravel filling. Standard vibratory hammers that clamp the hammer from the top are less suitable for this application as they reduce the efficiency by obstructing the hopper and also add to the working height. 

The casing is reusable and fitted with a funnel at the top to expedite the filling of the casing by the wheel loader. The 90DR has pull down winch that accelerates the performance of the vibratory hammer and allows the casing to penetrate harder layers. For driving through hard layers the casing can be fitted with water jetting nozzles at the tip, water jetting pipes can be fitted on the outside or the inside of the casing.

ICE ring vibrators are usually fitted with RF technology, this means that the vibrator can start up and shut down without resonance which is better for the piling rig. Contact your ICE sales rep to help you determine the right size hammer for your application.