This paper presents the results of a comprehensive study that investigated the influence of asperities and roughness on the shear responses of geomembrane/geotextile interfaces. This study was aimed at providing a scientific explanation of the effect of surface texturing on geomembrane/geotextile interfaces shear behaviour as well as to recommend the quantification of asperity and roughness characteristics which mobilises optimised shear strength for the considered interface. The GMB/ GTX interface shear tests were conducted according to ASTM D5321, under saturated conditions with the "305 mm by 305 mm" direct shear box at applied normal stresses of 25-400 kPa. The experimental outcome showed that the variation in geomembrane asperity height and surface roughness (from slightly textured to highly textured geomembranes) eventually mobilised an increase of 20° in the peak interface friction angle values. It was, however, observed that as the surface texturing was increased, more pronounced wear occurred which resulted in a relatively minimal increase of 6° in the large displacement friction angle. In addition, the geomembrane surface with asperity height of 1.2 mm and average surface areal roughness of 75 μm was observed to develop optimal peak friction angle for the considered geomembrane/geotextile interface. These observations were validated by means of post-shear deformation evaluation and it is anticipated that the findings presented herein would be useful in the design of geotechnical systems comprising of geomembrane/geotextile interface with enhanced stability and durability
The summary of this paper is focused on the result of a study that used quantitative measures of surface texture as the basis for examining the effects of asperities on the shear characteristics of geotextile-geomembrane interfaces. About 30 large direct shear tests were conducted to evaluate the geotextile-geomembrane interface shear strength properties. The results indicated a non-linear failure envelopes and strain softening behaviour at a normal stress range of 50 – 400 kPa. For most interface tested, the polyester-geotextiles resulted in higher shear strength as compared with polypropylene-geotextiles. Also, the polyester and polypropylene geotextile interface with the high asperity geomembrane produces a similar percentage increase in friction angle at the residual state. For textured geomembranes interfaced with both geotextile, polyester geotextile exhibited relatively less time before failure. Also, asperity height has a more pronounced effect than asperity density on the residual interface shear strength. The outcome of this study would provide a recommendation and guide that can lead to an improved basis for geosynthetics selection in various engineering application.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.