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A constitutive model for unsaturated soil interfaces
Author(s) -
Hamid Tariq B.,
Miller Gerald A.
Publication year - 2008
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.692
Subject(s) - dilatant , geotechnical engineering , constitutive equation , direct shear test , softening , suction , triaxial shear test , critical state soil mechanics , state variable , stress (linguistics) , shear (geology) , materials science , mechanics , engineering , structural engineering , composite material , thermodynamics , mechanical engineering , finite element method , physics , linguistics , philosophy
A constitutive model based on the disturbed state concept is presented to describe the behavior of interfaces in unsaturated soil. The model is an extension of an existing model developed for a sand–steel interface. As opposed to the original model, the modified model incorporates two independent stress variables, which are the net normal stress and matric suction. The saturated and dry state of the interface can be modeled as a special case using the constitutive model presented in this paper. The modified model is capable of capturing the main features of unsaturated interfaces observed during laboratory testing, including increasing shear strength and strain softening with increasing suction and net normal stress and increasing dilatancy with increasing suction. Laboratory tests were carried out on unsaturated interfaces in a modified direct shear test apparatus. The observed behavior of interfaces between unsaturated soil and steel plates (rough and smooth) is presented in comparison with model predictions. Copyright © 2008 John Wiley & Sons, Ltd.