Physical Properties and Allowable Bearing Capacity of Lateritic Soils from Meiganga (Adamawa Region-Cameroon) for Their Use in the Dimensioning of Foundations

This work aims to optimize the choice of foundations, reduce the risk of differential settlement and ensure the safety and durability of infrastructures. Analyses carried out on 45 reworked soil samples and 18 dynamic penetrometer test-points were used to characterize the physical properties of soils in Meiganga (Adamawa-Cameroon) and assess their mechanical strength for foundations purposes. The results shows that these soils are predominantly fine and plastic (52.05% passing the 0.080 mm sieve, average plasticity index of 28.02%), classified as A3 according to the GTR classification system. Their high dry densities (with an average of 1.61) and low porosity values (with an average of 39.01%) gives them a microporous character. The dynamic penetrometer test reveals a progressive increase in admissible stress with depth (from 0.63 kg/cm2 to over 10 kg/cm2), influencing the choice of foundations according to the neighborhood. Ngoa Ekelle and Rue 24 quarters (sectors) have high allowable stresses from a depth of 1 m, enabling shallow foundations between 1.5 and 3 m, while Sabongarie and Gbakoungue quarters require deep pile foundations due to a low surface bearing capacity. The soils at Pitoa and Zandaba quarters, which are loose at the surface but very resistant at depth, require deep foundations with long piles to attain the resistive base.