Environmental Engineering Reference
In-Depth Information
Figure 5.15.
Engineering log of cable tool drill hole (Courtesy South Australian Department of Mines).
It is considered that hammer drilling has little or no application in dam investigations
other than through rockfill of existing dams for which it is particularly suited. It can be
useful as a supplement to core drilling in the investigation of overburden depths and rock
quality at sites for spillways or quarries.
5.9.5
Rotary drilling
Drilling using a rotary machine (
Figure 5.16
,
Figure 5.17
and
Figure 5.18
) in soil and rock
can involve either core or non-core methods.
(a)
Non-core drilling
, sometimes called wash boring, involves the use of a solid roller,
button or drag bit at the end of drill rods. The bits break up or grind the full face of
