Influence of Surface Texture on the Interface Shear Capacity of Landfill Liner

 

Faisal Ali

Professor, Faculty of Engineering, National Defense University of Malaysia, Kuala Lumpur, Malaysia
e-mail: fahali@gmail.com

Firas A. Salman

Senior Lecturer, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
e-mail: firas@um.edu.my

Sumathi Subramaniam

Research Student, Faculty of Engineering, University of Malaya,, Kuala Lumpur, Malaysia
e-mail: sumathi6780@gmail.com

 

ABSTRACT

Geomembrane is one of the most widely used geosynthetics in various civil engineering applications. Its primary function is to act as a barrier for liquid and/or vapour. Smooth geomembrane is frequently used in combination with different soils, and however due to its low surface roughness, the main concern in the design is to ensure adequate shear capacity along the smooth geomembrane/soil interface. The use of smooth geomembrane will lead to low interface shear capacity between landfill liner components which can be considered as one of the major factors in the landfill slope stability failures. Modification of HDPE geomembrane from smooth surface to textured surface is therefore required to improve interface shear capacity of landfill liners. In this study, several interfaces of landfill liner components were tested by using large scale shear box. The combinations used were (1) Sand:Bentonite (100:5)/Smooth HDPE; (2) Sand:Bentonite (100:10)/Smooth HDPE; (3) Sand:Bentonite (100:5)/Textured HDPE; and (4) Sand:Bentonite (100:5)/Geotextile. All tests were conducted under optimum moisture condition. The interface capacities were compared with soil internal shear strength and the most critical interface was identified. The results show that interface shear capacity is enhanced by modifying the geomembrane surface texture.

Keywords: geosynthetics, landfill, interface properties, shear box

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