Geosynthetics in roads and pavements

Deployment of the Geosynthetic 

 

Unroll the geosynthetic on the prepared 

subgrade in the direction of construction traffic. 

Hold the geosynthetic in place with pins, 

staples, fill material or rocks. Adjacent rolls 

should overlap in the direction of the 

construction. Depending on the strength of the 

subgrade, the overlaps may have to be sewn.  

 

Overlap Specifications 

Soil Strength 

(CBR)

 

Overlap 

Unsewn 

in (cm)

 

Overlap Sewn 

in (cm)

 

Less than 1 

- 

9 (23) 

1 – 2 

38 (97) 

8 (20) 

2 – 3 

30 (76) 

3 (8) 

3 & Above 

24 (60) 

- 

 

 

Water sensitive subgrades can often be graded when dry 

 

 

When more challenging subgrades are encountered it is 

often more effective to leave vegetation and construction 

debris in place.  The geosynthetic will prevent migration 

of fill soils into the voids within the debris.