Vibro-piling rig. Like a massive vibrating....poker....Anne Summers device... :blink:
It vibrates the poker into the ground, remove, fill with stone, re-compact, fill with stone, re-compact agian etc. It compacts the stone "columns" vertically and laterally thus also compacting the ground in between the "columns". Ground stabilisation rather than piling.
We have one for hire if anyone needs it? :lol:
edit: spelling misakes corrected