Geoscience Reference
In-Depth Information
-
0%-10% soils and soft rocks.
-
5%-20% hard rocks.
•
∼
Typically wastage is
5%.
12.11 Practical maximum layer thickness
•
The practical maximum layer thickness for compaction depends on the material
to be compacted and equipment used.
•
The table below is for large equipment in large open areas.
Table 12.11
Practical maximum layer thickness for different roller types (Forssblad, 1981).
Roller type static weight (drum
Practical maximum layer thickness (m)
module weight in brackets)
Embankment
Pavement
Type
Weight (ton)
Rock fill
Sand/gravel
Silt
Clay
Subbase
Base
Towed
6
0.75
0.60
0.45
0.25
0.40
0.30
+
+
−
+
vibratory
10
1.50
1.00
0.70
0.35
0.60
0.40
+
+
+
−
−
+
rollers
15
2.00
1.50
1.00
0.50
0.80
-
+
+
+
−
−
6 Padfoot
-
0.60
+
0.45
+
0.30
0.40
-
10 Padfoot
-
1.00
0.70
0.40
0.60
-
+
+
Self
7 (3)
-
0.40
0.30
0.15
0.30
0.25
+
+
+
+
propelled
10 (5)
0.75
+
0.50
+
0.40
0.20
+
0.40
+
0.30
roller
15 (10)
1.50
1.00
0.70
0.35
0.60
0.40
+
+
+
+
+
+
8 (4) padfoot
-
0.40
+
0.30
+
0.20
0.30
-
11 (7) padfoot
-
0.60
0.40
0.30
0.40
-
+
+
15 (10) padfoot
-
1.00
0.70
0.40
0.60
-
+
+
Vibratory
2
-
0.30
0.20
0.10
0.20
+
0.15
tandem
7
-
0.40
0.30
0.15
0.30
0.25
+
+
+
rollers
10
-
0.50
0.35
0.20
0.40
0.30
+
+
+
+
13
-
+
0.60
+
0.45
0.25
+
0.45
+
0.35
18 Padfoot
-
0.90
0.70
0.40
0.60
-
+
+
•
Most suitable applications marked
+
.
•
Thickness in confined areas should be 200mm maximum loose lift thickness.
•
For small sized equipment (
<
1.5 ton) the applicable thickness is 1/2 to 1/3 of the
above.
12.12 Rolling resistance of wheeled plant
•
Rolling resistance
=
Force that must be overcome to pull a wheel load.
•
It depends on gradient of site and nature of trafficked area.
•
Rolling resistance
=
Rolling resistance factor
×
gross vehicle weight.
•
Table 12.12 indicates that maintenance of haul road helps to reduce operational
cost of plant.
•
A surface with no maintenance is expected to have 5 to 10 times the operating
cost of a good well maintained surface.
Search WWH ::
Custom Search