Etude du comportement mécanique d'un sol liquéfié traité et renforcé par les fibres de polypropylène

Abstract

There have been numerous experimental and numerical studies based on laboratory tests to examine the mechanical behavior of liquefiable soils. In this thesis we first studied the shear behavior of moderately dense sand-fiber and sand-silt- fiber compositions (Dr = 50%) in order to analyze the impact of polypropylene fibers on the behavior. shear of granular soils including strength, cohesion and friction angle. Then we studied the behavior of compressibility using the oedometric tests of Chlef sand to look for the effect of these fibers on the coefficient of compressibility (Cc). Finally, numerical simulations by the finite element method using the Plaxis 3D calculation code were carried out in order to predict the shear behavior of the sand in question. Organization of the dissertation • The first chapter presents a literature search on the different types of land instability and the factors influencing soil liquefaction, as well as reinforcement techniques and their selection criteria. • The second chapter presents the devices, the methodology and the procedures to follow to carry out the tests in the laboratory. • The third chapter consists in presenting the results of the tests of direct shearing with the box of Casagrande • The fourth chapter presents the results of the Oenometric tests. • The fifth chapter presents the results of numerical simulation and their comparison with the experimental tests. • Finally, the conclusion contains an overall summary of this study.