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AN EVALUATION OF THE ENVIRONMENTAL PROTECTION PROVIDED BY COMPOSITE LINER SYSTEMS

The effect of calcium uptake by hydration and diffusion from an adjacent calcium-rich soil on the performance of a geosynthetic clay liner (GCL) is examined for three cases. In Case 1 the GCL rested directly on a soil with a high calcium (1800 mg/l) concentration in the pore water (called “calcium rich soil” herein). Case 2 involved a GCL resting on 300 mm of soil with a low (200 - 300 mg/l) calcium concentration in the pore water (“foundation soil”) overlying the calcium rich soil. In the third (“control case”), the GCL only rested on the foundation soil. The overburden pressure was 15 kPa. The moisture content of GCL increased to 96%, 86% and 108% in the first 279 days for Cases 1, 2 and 3 respectively. Under isothermal conditions, the GCL moisture content decreased to 80% and 67% for Cases 1 and 2 respectively and increased to 113% for Case 3. After 1100 days, the hydraulic conductivity (k) of the GCL was 4×10-11 m/s for Case 3 but had increased up to about 7×10-11 m/s and 2×10-10 m/s for cases with and without the foundation layer respectively. The results are used to calibrate finite element models. A good correlation was found between k the bulk void ratio (eB) of GCL.
Leakage and contaminant transport through 10 mm diameter hole in a geomembrane in a composite liner involving a GCL is examined at a stress of 100 kPa for hydraulic heads of 0.3 or 1 m. When permeated with distilled water, the interface transmissivity (θ) was about 2.3 × 10 11 m2/s. After 800 days of permeation with 0.14M NaCl there was only about 3% increase in the flow despite an order of magnitude increase in GCL permeability near the hole because θ decreased from 2.3×10-11 m2/s to 1.1×10-11 m2/s and controlled the leakage despite the increase in GCL permeability. Numerical modeling demonstrated reasonable agreement with the observed transport. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2010-09-09 12:20:42.298

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/6031
Date09 September 2010
CreatorsABDELATTY, Khaled
ContributorsQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish, English
Detected LanguageEnglish
TypeThesis
RightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
RelationCanadian theses

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