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)
