Performance improvement of road embankment on Algeria Sabkha soils by geosynthetics

Abstract

Road engineers in Algeria like Tunisia, Arabi Saoudit, USA, India and Australia often face the challenge to design a solid road foundation on top of very soft soils which are characterized by Sabkha soils. These soils are very sensitive to moisture whereby complete collapse and large reduction in the bearing capacity are anticipated when these soils are in contact with water. With the help of geosynthetics innovative, economic and durable solutions can be offered to several situations where standard soil improvement techniques are still extensively used. This paper is interested by the construction technique of the road with reinforced embankment crossing the Sebkha flat of Chott El Hodna on 11 km length in the north middle of Algeria. The visual site observation and the analysis of the characteristics of the geotechnical investigation show that the surface layer is very weak bearing capacity, made up of deposit of mud with traces of silt, rests on a layer of thick muddy marl. The weak bearing capacity of the ground and the presence of water table make serious difficulties of construction. The design of this road was carried out using the FLAC -2D software specialized in geotechnics. The need for a reinforcement by geogrid associated with separation geotextile was well highlighted by the numerical simulations and confirmed by the difficulty reencountered in the placement of the two first embankment lift

Keywords

• Reinforced embankment, numerical simulation, geosynthetics, weak bearing capacity, road

References

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