Swelling Soil Settlement Prevention by Stabilization with Quicklime Column in Diamniadio (Senegal)

The risk of geotechnical drought, otherwise known as the risk of clay shrinkage and swelling, has long been identified by geotechnical engineers, and can be seen in many countries (USA, France, Canada, Ethiopia, etc.). In fact, clay soils show variations in volume when their water content varies. These variations affect the functioning of foundations and buildings in contact with the soil. This shrink-swell phenomenon is the cause of frequent disorders, which can range from a simple crack to considerable damage. The consequences are more spectacular in arid and semi-arid regions. In Senegal, this problem is of particular concern, especially in the context of the Diamniadio urban development project, which is based on geological formations prone to this phenomenon. However, it should be noted that the consequences of geotechnical drought on structures are conditioned by a range of factors of different kinds, which can be acted upon to prevent damage. One of these factors is the nature of the soil. Techniques for stabilizing soils by adding quicklime have been developed to deal with this risk. This article presents the reduction of settlements through the use of quicklime columns (from 1.85 mm to 1.054 mm). An analysis of the effect of column diameter and spacing on settlement is presented. The results show that settlement decreases as the columns are spaced closer together, giving a smaller settlement for a column spacing of 1 m.