Multi-scale understanding of sand-geosynthetic interface shear response through Micro-CT and shear band analysis

Khan, R and Latha, GM (2023) Multi-scale understanding of sand-geosynthetic interface shear response through Micro-CT and shear band analysis. In: Geotextiles and Geomembranes .

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Abstract

To understand the process of mobilisation of shear strength in sand-geosynthetic interfaces at a fundamental level, it is essential to precisely characterize the size and shape of the grains and the shear-induced surface changes in geosynthetics. In the current study, shear behaviour of dilative and non-dilative geosynthetics interfacing with sands of different morphological characteristics was analysed through interface shear tests and a gamut of digital imaging techniques. 3D shape parameters of sands such as sphericity, convexity, roundness, aspect ratio, and roughness were quantified at different scales using X-ray micro computed tomography (μCT) and optical profilometry. Interface shear tests revealed higher peak and residual friction angles for particles with greater irregularity, angularity, and surface texture. The surface texture of geotextile surfaces resulted in higher interface friction and higher vertical displacement compared to geomembrane surfaces, which showed completely non-dilative behaviour. Surface changes in geomembranes were quantified using laser profilometry. High resolution images obtained at different stages of shearing were analysed for quantifying the shear zone thickness using digital image correlation (DIC). Thickness of the shear bands, microscopic shearing mechanisms and shear strength are correlated to the multi-scale shape parameters of sands and surface changes in geosynthetic surfaces. © 2023

Item Type:	Journal Article
Publication:	Geotextiles and Geomembranes
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to Elsevier Ltd.
Keywords:	Aspect ratio; Computerized tomography; Friction; Geomembranes; Particle size analysis; Profilometry; Sand; Shear bands; Shear flow; Shearing; Strain measurement; Textures, Digital image correlations; Geosynthetic interfaces; Geosynthetics; Interface shear; Laser profilometry; Micro computed tomography; Multi-scales; Shear tests; Shears strength; Surface changes, Image correlation
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	21 Feb 2023 04:29
Last Modified:	21 Feb 2023 04:29
URI:	https://eprints.iisc.ac.in/id/eprint/80567

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