Résumé:
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.
