Liquid-Bridge Contact Model of Unsaturated Granular Materials and its Application in Discrete-Element Method
Publication: International Journal of Geomechanics
Volume 21, Issue 9
Abstract
In the past, the capillary effect is rarely considered for microcontact models when two adjacent particles are separated by a certain distance. In this paper, a liquid-bridge contact model of unsaturated particles is presented, which is applied to the discrete-element software PFC. Based on this, simulations of uniaxial tensile for unsaturated soils under (2D) situation are carried out, and influence of a water retention angle on uniaxial tensile strength are studied. The simulation results show that the uniaxial tensile strength of unsaturated soil decreases gradually with the increase of the water retention angle, obvious cracks generate at both ends of the soil samples, and the soil sample possesses a residual strength. According to the particle displacement field, velocity field, and contact force chain, the failure forms of samples with different water retention angles are determined. Based on the rose diagram of normal contact force, the changes of its direction and value during failure process are observed directly, so as to analyze the evolution law of contact force for unsaturated soils.
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Acknowledgments
This work was supported by the National Natural Science Foundation of China (U2034204, 52078031, U1834206) and the Natural Science Foundation of Beijing Municipality (8202038).
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Published In
International Journal of Geomechanics
Volume 21 • Issue 9 • September 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Oct 9, 2020
Accepted: Apr 16, 2021
Published online: Jul 5, 2021
Published in print: Sep 1, 2021
Discussion open until: Dec 5, 2021
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Cited by
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