Some studies on morphology of the coarse-grained soils

Characterization of Sediments for Sustainable Development: State of the Art

“…The morphology of sediments plays an important role in understanding their composition, grain formation due to mechanical and chemical degradation from the parent material, and transportation and depositional environment (Uday et al 2013). The interaction between different particles in the soil=sediments can be edge-to-edge (EE), edge-to-face (EF), or face-to-face (FF); depending on this interaction, different structures of the sediment are formed (van Olphen 1977;Bennett and Hulbert 1986).…”

“…The pore-fluid (pH), ionic concentration (IC), and moisture content (MC) of the sediments also govern the fabric formation, which affects geotechnical properties (viz., void ratio, coefficient of compressibility, effective surface area) of the sediments (Horowitz and Elrick 1987;Locat and Tanaka 1999;Phadnis and Santamarina 2011). The techniques employed for observation and identification of the morphological features of sediments are (a) Scanning Electron Microscopy (SEM) or Field-emission Gun Scanning Electron Microscopy (FEG-SEM) (Derenne et al 1992;Chen and Fang 2013) and Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) (Sloane and Kell 1966;Derenne et al 1992;Dias et al 2013), for analyzing the sediments at nanometric scale and studying the fracture surfaces; (b) micrograph techniques, laser optical microsocopy (LOM), and laser obscuration time method (LOTM) Singh 2005, 2007;Patel et al 2009;Uday et al 2013), for studying the grain morphology; (c) Mercury Intrusion Porosimetry (MIP) (Rootare and Prenzlow 1967;Enustun et al 1990;Nimmo 2004;Gumaste and Singh 2010), for understanding the pore-size distribution; and (d) X-ray diffraction (XRD), for measurement of the orientation and molecular packing (Seed and Chan 1959;Diamond 1971;Bertelle et al 1998;Locat and Tanaka 1999;Kolay and Singh 2001a,b) of the sediments. It has been noted that these techniques help in determining the shape (Uday et al 2013), orientation, and surface roughness of the particles (Diamond 1971;Hentschel and Page 2003;Padmakumar et al 2012;Chen and Fang 2013) in order to obtain a comprehensive picture about the morphology of the sediments.…”

“…It has been noted that these techniques help in determining the shape (Uday et al 2013), orientation, and surface roughness of the particles (Diamond 1971;Hentschel and Page 2003;Padmakumar et al 2012;Chen and Fang 2013) in order to obtain a comprehensive picture about the morphology of the sediments. In this context, the state-of-the-art instrumentation utilized by Uday et al (2013), who have highlighted the advantages and limitations of the aforementioned techniques for morphological examination of the fine-and coarse-grained soils, is worth mentioning.…”

Determining the shape of agricultural materials using spherical harmonics

“…These can be obtained by 3D scanning techniques. More recently, a technique based on X-ray micro-computed tomography has allowed the quantification and reconstruction of the 3D characteristics of particles and grains (Fonseca et al, 2012;Fonseca et al, 2013;Uday et al, 2013). However, this technique is highly sophisticated and requires a specialized operator; the cost is also an issue.…”

Sand Morphology Distribution Characteristics of the Southwest Buguli Desert

“…By comparing these methods he shows limitations of some methods in the study of particle morphology and suggests a better technique. Zhu [13] uses three indicators --angular, angular-rounded and rounded shapes of sand particles to represent the psephicity. His study concludes that rounded sand grains are less than 3%, and the rest are equally shared by the angular-rounded and angular sand grains.…”