Download Slope stability analysis of tailings dam embankments

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
Changes in undrained cohesion for different
slope angles β
140
Factor of safety
120
β = 2.9° (1V:20H)
100
β = 15°
80
β = 26.6° (1V:2H)
60
β = 30°
40
β = 45°
20
β = 60°
0
β = 75°
0
50
100
150
200
250
300
Undrained cohesion cu (kPa)
β = 84.3° (10V:1H)
10
9
8
Factor of safety
7
6
5
4
3
2
1
0
0
|
soft
|
50
firm
|
100
150
200
250
stiff
|
very stiff
Undrained cohesion cu (kPa)
300
|
Figure 6.4: Changes in undrained cohesion for different slope angles
Figure 6.4 shows that at shallow slope angles (< 30°), an increase in the undrained cohesion
improved the factor of safety. The factor of safety was less sensitive to changes in undrained
cohesion at angles greater than 30°. This can be seen in the sensitivity plot in Figure 6.5.
If a factor of safety of 1.5 is considered stable according to ANCOLD (2012), then the
minimum undrained cohesion for slope 1V:20H would be approximately 3.5 kPa, whereas for
slope 10V:1H, the minimum undrained cohesion would be approximately 60 kPa. This shows
that at shallow slope angles a weaker material can be used which may provide economic
70