Environmental Engineering Reference
In-Depth Information
Table 15.3.
Characteristics of Zone 2D in Brazilian CFRD (Sobrinho et al., 2000).
Dam
Foz do Areia
Segredo
Itá
Xingo
Machadinho
Itapebi
Grizzlied
Crushed
Crushed
Crushed
sound and
Crushed
sound
sound
sound
weathered
sound
Processed
Fill type
basalt
basalt
basalt
granite/gneiss
basalt
gneiss
Geometry
Bottom
13
8
10
12
10
12
width (m)
Crest
4
5
3
4
4/6
3
4
3
4
width (m)
Layer
0.4
0.4
0.4
0.4
0.4
0.4
(thickness m)
Gradation
Max. Size mm
100
75
75
100
75
100
25.4 mm %
50
45
60
70
50
80
passing
4.76 mm %
12
20
25
44
15
45
passing
0.150 mm %
1
2
5
10
7
11
passing
0.075 mm %
0
0
1
7
2
7
passing
Compaction
Horizontal
4/10 tonne
4/10 tonne
4/9 tonne
6/9 tonne
4/10 tonne
4/9 tonne
(passes/roller)
vibratory
vibratory
vibratory
vibratory
vibratory
vibratory
Upslope
6 passes
4/static
extruded
4/static
extruded
extruded
(passes/roller)
6/vibratory
wall
6/vibratory
wall
wall
Void Ratio
0.31
0.21
0.175
0.31
0.19
Density (t/m
3
)
2.12
2.27
2.15
2.12
1.97
2.20
Performance
Adequate
Adequate
Adequate
Cracking
Under
Under
during
Settlement
construction
construction
construction
Table 15.4.
Desirable specification for Zone 2D.
Sherard (1985b)
ICOLD (1989a)
Amaya & Marulanda (2000)
Size (mm)
% finer
% finer
% finer
75
90-100
90-100
90-100
37
70-95
70-100
70-100
19
55-80
55-80
65-100
4.76
35-55
35-55
40-55
0.6
8-30
8-30
10-22
0.075
2-12
5-15
4-8
15.2.2
Zones 2E, 3A and 3B - Fine rockfill, rockfill and coarse rockfill
15.2.2.1
General requirements
The basic requirements for rockfill in a CFRD are:
- The rockfill should be free draining to avoid build-up of pore pressure during construc-
tion, and to allow controlled drainage of water which might leak through the faceplate;
