A theoretical retention model for unsaturated uniform and graded soils

¹ Gaiatech, 22 rue Antoine Chollier, 38170, Seyssinet, France
² L3S-R, Université Joseph Fourier, Grenoble, BP53, 38041, Grenoble, France
³ EGIS Géotechnique, 3, rue Docteur Schweitzer, 38180, Seyssins, France
⁴ LOMC, CNRS UMR 6294, Université du Havre, BP 540, 75058 Le Havre, France
⁵ GCD,Ecole Nationale des Travaux Publics de l’Etat, 3 rue Maurice Audin, 69518, Vaulx en Velin France

^a Corresponding author: monnet.jacques@wanadoo.fr

Abstract

Modelling the relation between the degree of saturation and the suction (ie retention curve) is an important challenge for geotechnical engineering. It has a huge influence on the behavior of large soil constructions as levees, embankments, road earthworks. We present here a theoretical model of retention curve which considers physical relations of unsaturated soils. With this approach, there is no need to assume particular shapes of the retention curves, which are a consequence of the physical assumptions. The present study is focused on a theoretical model based on elastic spherical particle arrangement. As a first step a uniform model is presented with a single diameter of soil particle. A second step extends the use of the model to graded soils. The model uses only 5 physical parameters. It is compared with the experimental retention curve of two different samples of glass uniform particles and two different graded soils, a graded glass sample and the Livet-Gavet loam. It shows its ability to model the experimental curves and a better agreement than the former theory of Brooks and Corey (1966). This current publication is funded by the French National Project «Terredurable» (ANR 2011),.