Uniqueness of a Constitutive Shear Modulus Surface for Unsaturated Soils
Publication: International Journal of Geomechanics
Volume 15, Issue 6
Abstract
The measurement of shear modulus at small strains in unsaturated soil is critical to evaluating the deformation behavior of soils at working loads. However, little has been done to determine if the small-strain shear modulus surface is unique during variation in either net mean stress or matric suction. In this context, uniqueness is defined as similar samples subjected to different stress paths that converge to the same stress state. Research is presented herein in which a unique constitutive shear modulus surface was established by independently controlling mean net and matric suction stress in a modified resonant column apparatus. Uniqueness was also investigated using data extracted from literature studies. Uniqueness of the shear modulus surface was shown for single-direction stress and hydraulic paths, by the convergence of modulus and by the agreement between predicted and measured modulus. The presence of a unique shear modulus surface allows for the use of a constitutive relationship based on soil type that describes the small-strain shear modulus in terms of the stress state variables.
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Acknowledgments
The authors would like to acknowledge the assistance of Tommy Hopkins and Tony Beckham, both formerly of the Geotechnology Section of the Kentucky Transportation Center. Partial funding for this research was provided by the University of Kentucky Department of Civil Engineering and the Kentucky Transportation Center.
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Information & Authors
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Published In
International Journal of Geomechanics
Volume 15 • Issue 6 • December 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Nov 8, 2012
Accepted: Nov 13, 2014
Published online: Apr 14, 2015
Discussion open until: Sep 14, 2015
Published in print: Dec 1, 2015
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