Unified Elastic Modulus Characteristic Curve Equation for Variably Saturated Soils
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 148, Issue 1
Abstract
A soil’s elastic modulus is a fundamental property defining the soil’s reversible stress-strain relation under mechanical and environmental loadings. It has been observed that a soil’s elastic modulus can increase up to several orders of magnitude from fully saturated to dry conditions due to two distinct soil water retention mechanisms: adsorption and capillarity. Adsorption affects interparticle stress through van der Waals and electrostatic attraction and interparticle friction coefficient through water film retained by soil sorptive potential. Capillarity governs interparticle stress through capillary pressure and surface tension. The onset and scaling laws of the two mechanisms depend on the soil properties of specific surface area, pore-size distribution, cation exchange capacity, and soil mineralogy. These mechanisms are unified by a proposed elastic modulus characteristic curve (EMCC) equation. It is demonstrated that the proposed EMCC equation can well describe the moisture-dependent elastic modulus of a wide array of soils. Further, an interrelation among the EMCC equation, suction stress and soil shrinkage curves is established, which can greatly facilitate predicting suction stress from soil shrinkage curves and vice versa, further validating the EMCC equation in capturing soil’s hydromechanical behavior. The practical importance of the EMCC equation is demonstrated through prediction of ground heave of various soils due to a hypothetical flooding event.
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Data Availability Statement
All data, models, and code generated or used during the study are available from the corresponding author.
Acknowledgments
This research was sponsored in part by the National Natural Science Foundation of China (52078208 and 52090083) to CZ.
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Journal of Geotechnical and Geoenvironmental Engineering
Volume 148 • Issue 1 • January 2022
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© 2021 American Society of Civil Engineers.
History
Received: Apr 15, 2021
Accepted: Sep 15, 2021
Published online: Oct 21, 2021
Published in print: Jan 1, 2022
Discussion open until: Mar 21, 2022
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