Shear Strength Equations for Unsaturated Soil under Drying and Wetting
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VIEW THE REPLYPublication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 136, Issue 4
Abstract
Shear strength of unsaturated soil is an important engineering property in various geotechnical designs. In response to varying climatic conditions, unsaturated soil behaves differently under the drying and wetting processes due to hysteresis. Many research works were conducted and numerous equations were proposed for unsaturated shear strength, however, most of them were limited to the soil under the drying process. In this study, shear strength equations were categorized according to the nature of equation, i.e., fitting and prediction type equations. The purpose of this study is to propose prediction type shear strength equations for unsaturated soil under drying and wetting. Twelve published shear strength equations were selected for evaluation. A series of unsaturated consolidated drained triaxial tests were conducted on statically compacted sand-kaolin specimens under drying and wetting to examine the validity of the proposed equations. The experimental results indicated that the specimens on the drying path had a higher shear strength and exhibited more ductility, less stiffness, and contraction during shearing while the specimens on the wetting path had a lower shear strength and exhibited more brittleness, more stiffness, and dilation during shearing. The proposed equations were shown to provide the best predictions on the drying and wetting shear strength results from this study as well as published data in the comparison study.
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Acknowledgments
This project was supported by the research grant from the collaboration project between Housing and Development Board (HDB), Singapore and Nanyang Technological University (NTU). The first writer would like to acknowledge the research scholarship provided by NTU, Singapore. The assistance from the staff of Geotechnical Laboratory, school of Civil and Environmental Engineering, NTU during the research is highly appreciated.
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Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 136 • Issue 4 • April 2010
Pages: 594 - 606
Copyright
© 2010 ASCE.
History
Received: Jan 19, 2009
Accepted: Oct 5, 2009
Published online: Oct 6, 2009
Published in print: Apr 2010
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