Influence de la perméabilité et la fraction en fines non plastiques sur le potentiel de liquéfaction d’un sol sablonneux

Abstract

Liquefaction is a process in which, saturated looses temporarily its strength and behave like a liquid. The work in this thesis is a contribution in an analyzing the behavior of granular soils under monotonic loading. The objective of this research is to study the effects of some parameters on the behavior of the possible liquefaction of the sand of Kharrouba, (Mostaganem), especially: the initial density, confining pressure, the fraction of low- plastic fine and essentially permeability. The first part includes a literature review on the work already done on the effects of some parameters on the resistance to liquefaction of silty sand, historical cases of liquefaction and the mechanical behavior of sandy soils are illustrated in detail. As well, it is presented in this section also, a bibliographical analysis on the soil permeability and evaluation of permeability and factors affecting it. The second part of this work presents the used equipment, the followed procedure and the materials under investigation, the results of triaxial test under undrained conditions under monotonic loading and discusses the influence of some parameters on the behavior of sandsilt mixtures under consideration. The results of various undrained monotonic triaxial on silty sand samples, loose and medium dense are analyzed and discussed in detent; it has been shown that there is a correlation between the critical undrained shear and the fines content, that is to say, there is a contractive behavior when the fines content is less than 30%. Beyond 30% of fines content the behavior becomes dilative.