Civil Engineering Reference
In-Depth Information
Table 2-5
Properties of rock and rock mass that can be determined by drilling, from DIN 4021.
Row
Column
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Detectable properties
Drilling process
Drilled samples
Drill hole
Certain impro-
vement of de-
tection through
combination of the
following columns
Core
Cuttings
1
Type (grain size, mineral content)
+
9 & 10
2
Formation (grain shape, arrange-
ment, bonding, spatial filling)
1 & 9 & 10
9 & 10 & 13
+
3
Colour, stai
ning
+
+
9 & 10 & 11
4
Weathering
condition
+
+
+
+
1 & 9 & 10 & 11
5
Decompos
i
tion (air/water/frost)
+
+
+
+
+
+
+
9 & 10
6
Permeabilit
y
+
+
7
Strength, du
ctility
+
+
8
Rock bound
aries
+
+
+
1 & 9 & 10 & 11
9
s
trike and dip
10
+
+
f
requency (spacing)
11
formati
on and course
+
12
filling, c
oating
+
+
+
+
+
9 & 10 & 11
13
Cavities
14
Permeabilit
y
+
+
+
+
15
Strength, du
ctility
+
+
+
+
Not generally detectable, but frequently
detectable in certain ground types
1
) Feed rate, type and condition of drill bit, pressure, flushing pressure and revolutions
3
) Before performance of any drillhole support such as casing or consolidation
2
) Taking into consideration the type of flushing fluid and additives
Detectable
Not detectable
Incompletely detectable, but detectable with a
certain experience
4
) See Section 4.2 regarding core taking with orientation
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