Modeling of Clay Liner Desiccation
Publication: International Journal of Geomechanics
Volume 5, Issue 1
Abstract
The potential for the desiccation of clay liner component of composite liners due to temperature field generated by breakdown of organic matter in municipal solid waste landfills is examined using a model proposed by Zhou and Rowe. In these analyses, a set of fully coupled governing equations expressed in terms of displacement, capillary pressure, air pressure, and temperature increase are used, and numerical results are solved by using finite element method with a mass-conservative numerical scheme. The model results are shown to be in encouraging agreement with experimental data for a problem involving heating of a landfill liner. The fully coupled transient fields (temperature, horizontal stress change, suction head, and volumetric water content) are then examined for two types of composite liner system, one involving a geomembrane over a compacted clay liner (CCL) and the other involving a geomembrane over a geosynthetic clay liner (GCL). It is shown that there can be significant water loss and horizontal stress change in both the CCL and GCL liner even with a temperature increase as small as 20°C. The time to reach steady state decreases as boundary temperature increases. Under a 30°C temperature increase, it takes 5 years to reach the steady state water content with a GCL liner but 50 years with a CCL liner. The effects of various parameters, such as hydraulic conductivity and thickness of the liner, on the performance of the liner are discussed.
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Acknowledgments
The financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC), Terrafix Geosynthetics Inc, the Centre for Research in Earth and Space Technology (CRESTech), and Naue Fasertechnik GmbH & Co. are gratefully acknowledged.
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Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 5 • Issue 1 • March 2005
Pages: 1 - 9
Copyright
© 2005 ASCE.
History
Received: Jul 1, 2002
Accepted: Jul 28, 2004
Published online: Mar 1, 2005
Published in print: Mar 2005
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