Post on 07-Jan-2016
description
Shear strength of rock discontinuities
9
0 10 50 60
Schmidt hardness - Type L hammer
Ham
mer
orie
ntat
ion
50 100
150
250
Average dispersion of strengthfor most rocks - MPa
20
22
24
26
28
3032
Uni
t w
eigh
t of
roc
k - k
N/m
3
400350300
250
200
150
10090807060
50
40
30
20
10
Uni
axia
l com
pres
sive
stre
ngth
- M
Pa
20 30 40
0 10 20 30 40 50 60
0 10 20 30 40 50 60
0 10 20 30 40 50 60
0 10 20 30 40 50 60
200
+ + + + +|| | | |
Figure 7: Estimate of joint wall compressive strength from Schmidt hardness.