Geotechnical identification of soil deposits and clay sensitivity evaluation: A case study from East Algeria

This article provides an overview of a comprehensive study conducted in the Tebessa region of Algeria to identify and characterize sensitive soils susceptible to swelling. This phenomenon poses significant challenges to construction activities and infrastructure development in the area. The study employed a multidisciplinary approach, combining geotechnical and mineralogical analyses to understand the behavior of sensitive soils in the region. Geotechnical investigations involved laboratory identification tests, including Atterberg limits, grain size analysis, methylene blue value, sedimentometry, as well as mechanical tests: oedometer swelling and compressibility tests. Additionally, over 110 boreholes in four sectors were drilled in order to collect soil samples for the analysis. Classification of the studied soils was performed based on grain size distribution, Atterberg limits, and geotechnical properties, utilizing classification systems like LPC and GTR. Results indicated that the sensitive soils in the Tebessa region predominantly belonged to highly plastic clayey categories, exhibiting medium to extremely high swelling potential. Mineralogical analysis through X-ray diffraction provided insights into the composition of the clay fraction, with a focus on identifying swelling clay minerals, such as smectites. The study identified a significant presence of smectites in the soil samples, which are known for their high swelling potential. Integrating geotechnical and mineralogical analyses allows engineers to correlate mineral compositions with soil behaviors such as compaction, consolidation, and shear strength. This correlation predicts how the soil will respond to engineering activities such as construction and slope stability. In the Tebessa region, this integration improves the understanding of clayey soil behavior, aiding informed decisions for sustainable development and resilient infrastructure.