Rotational bores with extraction of a continuous
sample
The
general principle consists of exerting pressure on the terrain and
at the same time, a rotative action with a metal rod connected to
a rotating chuck. The extraction of material is carried out by pumping
water or other perforation fluid.
The depth reached depends on the diameter of the perforation, the
rods and the bore and can reach 100m.
Depending on the type of terrain a different cone will be used:
widia, consisting of wolfram carbide and used on soft rocks or diamonds
used for harder terrain.
The majority of rotational work undertaken by our firm is carried
out with the TP30 rotative bore belonging to another company to
which Geonival, Geologia Aplicada s.l. belongs.
This
bore enables us to obtain undamaged samples and also to carry out
the Standard Penetration Test (SPT)
By examining the subsoil with the extraction of the continuous sample
we obtain the stratigraphic column of the study zone.
We
also obtain the physiochemical and geomechanical parameters at the
depth we want, centimetre by centimetre, which, together with geological
knowledge of the zone enables us to establish precise conclusions.
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