By Timothy D. Stark
Q: Is there a maximum slope angle for geosynthetic-lined slopes?
A: Yes there is, and the slope angle should not exceed the lowest geosynthetic interface friction angle, δ, of the system. The slope angle should not exceed δ because this condition can/will lead to tension developing in the geosynthetics and possibly progressive failure of the slope. Geosynthetics will stretch and possibly tear under tension because they are not designed to be under tension. The only geosynthetic that is designed to be under tension are geosynthetic reinforcement products, such as geogrids and high strength geotextiles.