Avaliação do uso de método dos elementos finitos para estimar o comportamento mecânico de um solo proveniente da bacia sedimentar de Curitiba

Abstract

This study seeks to determine soil shear strength parameters, including cohesion and internal friction angle, through triaxial compression tests and to assess the efficacy of the Finite Element Method (FEM) in simulating these tests. The research is divided into two stages to perform a comparative analysis of laboratory results and numerical simulations using the perfect elastoplastic constitutive model with Mohr-Coulomb rupture criteria. The first stage was carried out in the laboratory, while the second was done through modeling. The experimental data reveal that the soil exhibits shear strength parameters, under total stresses, of approximately 40 kPa for cohesion and 5.1° for the internal friction angle. For effective stresses, the parameters are 30 kPa for cohesion and 16° for the internal friction angle. Numerical simulations conducted with confining stresses lower than the pre-consolidation stress estimate cohesion at 20 kPa and the friction angle at 14°, yielding percentage discrepancies of 17% and 34%, respectively, relative to laboratory values. The comparison of numerical and experimental results indicates significant deviations, suggesting that the simplified Mohr-Coulomb model may inadequately represent the complex behaviour of soil. Nevertheless, numerical modelling remains crucial in geotechnical analysis, particularly in scenarios where extensive laboratory testing is impractical. The study underscores the necessity for advancing constitutive models and rigorously calibrating input parameters to improve prediction accuracy and enhance the reliability of geotechnical analyses in engineering projects.