Essential features of compacted silty sand behavior via suction-controlled triaxial testing

¹ Faculty Research Associate, University of Texas at Arlington, Arlington, Texas 76019, USA
² Professor, University of Texas at Arlington, Arlington, Texas 76019, USA
³ Professor, University of Texas at Arlington, Arlington, Texas 76019, USA

^a Corresponding author: ujwalkumar.patil@mavs.uta.edu

Abstract

The main intent of this work was to gain further insight into some of the limitations (and potential) of the Barcelona Basic Model (BBM) in predicting the stress-strain response of compacted unsaturated soils that are prone to post-peak strain-induced softening during suction-controlled shearing. To this aim, a comprehensive series of suc-tion-controlled tests were conducted on statically compacted specimens of silty sand using a recently implemented, servo/suction-controlled, double-walled triaxial apparatus. The brittle and dilatant nature of the test soil, as expected, did not allow for good agreement between the experimental and BBM predicted stress-strain responses of compacted silty sand, since post-peak softening was not adequately captured. BBM simulations, however, held reasonably good during the early shearing stage (up to about 1-2% total shear strain), and at higher values of shear strain, that is, close to critical state condition.