Abstract
CORRELATION BETWEEN ELASTIC PARAMETERS AND THE CBR INDEX: APPLICATION IN FOKAMEZO LATERITIC SOILS – EVALUATION METRICS
Manefouet Kentsa Bertille Ilalie*, Meladem Tsobgni Leslie Merveille, Njiosseu Tanko Evine
ABSTRACT
This study consisted of the characterisation of the lateritic gravels of Fokamezo in the southern slope of Bambouto?s Mountains with the aim to propose correlation models between the CBR and the moduli of elasticity in the optimization of pavement design. Geotechnical laboratory identification tests were carried out on four samples taken from the study area. The results obtained show that the material studied has a specific density of 2.6 t/m3. The average dry density at the Proctor optimum obtained is 1.706 t/m3 for an optimum water content of 15.9%. With an average CBR of 59.9, this material belongs to the bearing capacity class S5. The average Young's modulus of 221.562 MPA obtained by punching, an average Young's modulus of 29.7019 MPa obtained by compression and an average Poisson's ratio of 0.381 were recorded for this material. A polynomial correlation of CBR values and moduli of elasticity is proposed: E = 0.8676(CBR)2 ? 85.529(CBR) + 2231, with R2 =0.99; E in MPa), and ? = 0,0152(CBR)2 - 1,7659(CBR) + 51,22; with R2 = 0,99). The E=f(CBR) models are efficient with the NS criteria of 0.9 while the =f(CBR) models are exact and fair with the MAE, MSE, RMSE and RMSLE values close to 0. This soil can be used as a sub-base and base layers material for all types of traffic.
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