Continuous undisturbed environmental sampling through all formations.
Installation of geotechnical instruments inside cased borehole.
Effective in landfill, marine sediments and gravels.
Bulk soil sampling up to 250mm.
Sonic drill rigs advance a concentric hollow drill pipe using rotation in conjunction with axial vibration of the drill stem.
After each stage of drill stem advancement, the inner string is removed with a core of drill cuttings while the temporary ‘casing" string remains to hold the borehole open. The cuttings can be removed nearly intact from the inner casing for examination of the stratigraphy prior to sampling or disposal.
Because there are no auger flights to increase the borehole diameter, the quantity of cuttings removed from the hole is minimised as compared to hollow stem augering. With moderate rotation, smearing of the formation materials on the borehole walls is greatly reduced. This drilling method is useful in formations, from flowing sands to volcanic flows.
In flowing sands, the drill casings can be filled and/or pressurized with potable water to prevent excess entry of formation materials into the drill string.
Sonic drilling allows a larger diameter temporary casing to be set into a confining layer while drilling proceeds into deeper aquifers. This temporary casing is then removed during the grouting operation.
Sonic drilling has proven to be the best method for the installation of leachate injection/extraction bores and gas monitoring wells through landfill. Geoprobe and Geo-technical rigs will always struggle in these conditions.
Drilling with Sonic machines off barges overwater is very effective given the effective sediment sampling and ability to quickly case of loose sediments prior to diamond coring.
Sonic Drilling Services Brisbane, Melbourne, Perth, Adelaide