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Geotechnical drilling
When, after a probing, not all the questions are answered, it’s commonly
decided to perform drillings for sample taking. Usually more information
is required about the mechanic properties of the soil (like
compressibility and load ability) and the permeability for groundwater
in the separate layers. If the mechanic qualities of the soil need
investigation, undisturbed soil-samples are taken, with which
experiments can be done in a geotechnical laboratory. The bearing
capacity of the soil is derived from the soil type and from observations
made by the drillmaster during the drilling process. He classifies the
soil by type (sand, gravel, clay or bog) and ads information about the
consistence (weak, rigid, loose, solid etc). The Dutch drillmaster
Ackermann came with the idea of a thin-walled steel tube of about 40
centimetre length and 66 millimetres in diameter, fitted with a valve to
prevent the sample from slipping out, whilst pulling it out of the
ground. Nowadays this is the most accepted technique for geotechnical
sample-taking.
GWTR can take these samples for u by using the aqua lock 50mm or 70mm.
It’s possible to use Ackermann coring apparatus as well. Various types
of sampling can be performed in combination with the Compact Roto Sonic.
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