Environmental Engineering Reference
In-Depth Information
Figure 5.16.
Rotary drill rig (a) Side view. Mast can be tilted to drill angled holes. (b) Rear view show-
ing top drive hydraulic motor. (c) Dismantled core barrel showing inner tube, core catcher
and drill bit (courtesy Jeffery and Katauskas).
the bottom of the hole. The soil and rock fragments are removed by the circulating
fluid - commonly water. Samples from non-core rotary drilling through soil and rock
are usually a slurry of water and fine-grained material. This leads to poor identifica-
tion of the materials.
It is usual to collect thin-walled tube samples of cohesive soils for more accurate
material description and laboratory testing and to carry out
in situ
testing in the
borehole.
