Performance of an Instrumented Slope Covered by a Capillary Barrier System
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 138, Issue 4
Abstract
A capillary barrier as a cover system is a two-layer system of distinct hydraulic properties to prevent water infiltration into the underlying soil by utilizing unsaturated soil mechanics principles. This paper illustrates the application of the capillary barrier system on a slope that experienced shallow slip failures to prevent future rainfall-induced slope failures. In this study, the capillary barrier system was designed as a cover system for residual soil slopes with a steep slope angle under heavy rainfall conditions of the tropics. The capillary barrier system was constructed using fine sand as the fine-grained layer and granite chips as the coarse-grained layer. Both layers were contained in a cellular confinement system. The slope was instrumented with tensiometers and piezometers. The tensiometers were installed at different depths from about 0.5 m to 2.0 m below the slope surface. An adjacent original slope without the capillary barrier system was also instrumented using tensiometers to investigate the performance and effectiveness of the capillary barrier system in reducing rainwater infiltration and maintaining negative pore-water pressure in the slope. The detailed installation of a matric suction measurement device is discussed comprehensively in this paper. The measurement results showed that the capillary barrier system was effective in maintaining the negative pore-water pressures during rainfalls, particularly on the crest of the slope.
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Acknowledgments
The work described in this paper was supported by the Housing and Development Board and Nanyang Technological University, Singapore.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 138 • Issue 4 • April 2012
Pages: 481 - 490
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Sep 27, 2010
Accepted: Jul 12, 2011
Published online: Aug 3, 2011
Published in print: Apr 1, 2012
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