Etude du Comportement d’un Sol Non Cohérent à la Liquéfaction Amélioré par Inclusion

Abstract

The work of this thesis is to undertake an experimental study on the behavior of a sand liquefaction and also the effect of some parameters on the mechanical behavior of the soil. It is presented in this work a bibliographical study on the phenomenon of soil liquefaction and the effect of some parameters on resistance to liquefaction. Also, it is presented the liquefaction potential evaluation methods and the methods of treatment and improvement of liquefiable soils. An experimental investigation was carried out on sand collected in the eastern part of the city of Mostaganem (the coastal area of Kharrouba). This area knows many of the building construction projects where important disorders frequently appear in constructions based on these sandy massifs. Samples of this soil were subjected to tests for characterization and identification. To study the influence of fines and size characteristics on the mechanical behavior (strength at peak and residual), a reconstituted soil with fine grades ranging from 0 to 50% was subjected to triaxial tests with monotonic loading in undrained conditions. The experimental program was carried out with two initial relative densities 15% and 45 % and with three confining pressures 100, 200 and 300 kPa. The results of these tests have shown that the sol has exhibited a contractive behavior when the fines content is less than 30%. Beyond 30%, the behavior becomes dilative. It is noted from the results that there is an unstable medium deformation behavior, followed by a large deformation resistance boost, which leads us to say that we are facing limited liquefaction phenomenon.