Three-Dimensional DEM Analysis of Axially Loaded Geogrid-Encased Stone Column in Clay Bed
Publication: International Journal of Geomechanics
Volume 20, Issue 3
Abstract
The discrete-element method (DEM) was employed in this study to analyze the micromechanical behavior of an axially loaded geogrid-encased stone column (GESC) installed in a clay bed. A three-dimensional DEM model was developed to simulate a partially encased stone column in the laboratory test under a plate loading condition. The aggregate, the geogrid encasement, and the surrounding soil were simulated using particles with different sizes and micromechanical properties. The load-displacement behavior of the DEM model closely matched the experimental result during the loading process. This study investigated the vertical and radial stresses in the column and its surrounding soil, the porosity change and particle movement in the column, and the contact force distributions before and after loading. The interaction and the interlocking effect between particles were different in the encased and unreinforced sections due to the existence of the geogrid encasement. The surrounding soil developed high vertical and radial stresses in the layers below the base of the geogrid encasement due to the strong interaction between the aggregate and the soil. The maximum coefficient of radial stress (2.4) in the encased column was approximately half the coefficient of passive earth pressure (4.6). The current design method overestimated the bearing capacity of the GESC based on the coefficient of passive earth pressure.
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Data Availability Statement
Some or all data, models, or code generated or used during the study are available from the corresponding author by request.
Acknowledgments
This research was funded by the National Key Research and Development Program of China (Grant No. 2016YFC0800200) and was conducted while the first author visited the University of Kansas as a visiting scholar, which was supported by the China Scholarship Council (Grant No. 201406130006). The first author was granted temporary rights to use the PFC3D software through the Itasca Educational Partnership (IEP). This support is appreciated.
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Information & Authors
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Published In
International Journal of Geomechanics
Volume 20 • Issue 3 • March 2020
Copyright
©2019 American Society of Civil Engineers.
History
Received: Feb 23, 2019
Accepted: Aug 13, 2019
Published online: Dec 17, 2019
Published in print: Mar 1, 2020
Discussion open until: May 17, 2020
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