Geoscience Reference
In-Depth Information
Table 12.12 Rolling resistance of wheeled plant (Horner, 1988).
Haul road conditions
Rolling resistance Factor
Surface
Condition
Kg/t
An equivalent
gradient
Hard, smooth
Stabilized surface roadway, no penetration
20
2%
under load, well maintained
Firm, smooth
Rolling roadway with dirt or light surfacing, some
32.5
3%
flexing under load, periodically maintained
With snow
Packed
25
2.5%
Loose
45
4.5%
Dirt roadway
Rutted, flexing under load, little maintenance,
50
5
25-50 mm tyre penetration
Rutted dirt roadway
Rutted, soft under travel, no maintenance,
75
7.5%
100-150 mm tyre penetration
Sand/gravel surface
Loose
100
10%
Clay surface
Soft muddy rutted, no maintenance
100-200
10-20%
12.13 Compaction requirements for various applications
The compaction levels should be based on the type of application.
Compaction assumes a suitable material, as well as adequate support from the
underlying material.
A very high compaction on a highly expansive clay can have an adverse effect in
increasing swelling potential.
The subgrade thickness is typically considered to be 1.0m, but this varies
depending on the application. Refer Section 13.1.
Table 12.13 Compaction levels for different applications.
Class
Application
Compaction level
1
Pavements
Extremely high
Upper 0.5 m of subgrade under buildings
2
Upper 1.5 m of subgrade under airport pavements
Very high
Upper 1.0 m of subgrade under rail tracks
Upper 0.75 m of subgrade under pavements
Upper 3 m of fills supporting 1 or 2 story buildings
3
Deeper parts to 3 m of fills under pavements
High
Deeper arts of ills under buildings
Lining for canal or small reservoir
Earth dams
Lining for landfills
4
All other fills requiring some degree of
Normal
strength or incompressibility
Backfill in pipe or utility trenches
Drainage blanket or filter (Gravels only)
5
Landscaping material
Nominal
Capping layers (not part of pavements)
Immediately behind retaining walls (self compacting
material “Drainage Gravel'' typical)
 
 
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