14 Feb 03
reinforcement recommended as shown in Table 5. A minimum aggregate thickness of 6 inches
is recommended for aggregate-surfaced pavements. Aggregate-surfaced design examples are
provided in Appendix A. Note that standard frost design procedures should be used for regions
in which significant frost penetration occurs.
Reinforced Bearing Capacity Factors, Nc1, for Aggregate-Surfaced Pavements
Step 1: Determine Design Subgrade Soil Strength and Geosynthetic Applicability
CBR < 0.5
0.5 < CBR < 2.0
2.0 < CBR < 4.0
CBR > 4.0
A geotextile is required for
Use a geotextile
Both a geogrid and a
fine-grained subgrades. A
and a geogrid at
geogrid may also be cost-
recommended. Use this
effective. Perform a life
design procedure for
cycle cost analysis.
Use TM 5-822-12
The unreinforced bearing capacity factor, Nc, is 2.8.
Both a geotextile and a geogrid are recommended. The geotextile serves primarily as a
Use a factor of 3.6 for conservative geotextile-reinforced pavement designs.
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