## Embankment Slopes on Compressible Soils

### Definition :

Failures in compacted earth embankments (e.g., road fills) overlying soft clay, silt, or peat deposits typically exhibit the following characteristics:

Failure Mechanism:

- Rotational slip surfaces tangent to the base of the compressible layer when relatively thin

- Critical dependence on the underlying weak stratum thickness

Long-Term Stability Concerns:

Failures in compacted soil embankments (e.g., road fills) overlying soft clay, silt, or peat deposits typically exhibit the following characteristics:

Failure Mechanism:

Rotational slip surfaces tangent to the base of the soft layer when relatively thin

Potential creep-induced foundation deformation when the safety factor is marginally above 1.0, leading to:

- Excessive embankment settlement

- Lateral heaving of the soft stratum

- Strength reduction in the embankment material

### Example :

Case Example:

The current road embankment construction across Chott El Hodna's sebkha demonstrates these challenges. The firsrt photo shows significant sub-grade deformations during low-water periods. Despite surface water presence (second photo)), construction was enabled through:

- Filtration geotextiles

- Reinforcement geogrids (visible in photo)

Embankment on compressible soil (Chott El Hodna)
Junction of embankment sections during construction