Etude en laboratoire de l’effet du rapport de surconsolidation sur le comportement non drainé des sols.

摘要

In this paper, we present a laboratory study of the influence of overconsolidation ratio on the undrained behavior of silty sand. This study is based on the undrained triaxial tests which were performed for the overconsolidation ratio at OCR = 1, 2, 4 and 8, with fractions of fines of mixture varying between 0 % and 40 %. Tests were carried out on samples with an relative density Dr= 50% and confinement pressure σ’c = 100 kPa . The article is divided into two main parts. The first one presents the soils studied and the second one gives an analysis of the results and discusses the influence of overconsolidation ratio on the shear strength of the soil. The tests show that the shear strength of the soil increases with increasing overconsolidation ratio, resulting of in an increase of dilatancy . Increasing the fines content ( Fc ) ranging from 0 to 40 % , increases the phase of contractancy and consequently reducing the phase of dilatancy of the tested soil . A decrease in angle of internal friction (φ °) is due to a high content of fines (Fc = 40% ) and at OCR = 1 (soil normally consolidated).