GIS-Based Quantitative Analysis of Orientation Anisotropy of Contaminant Barrier Particles Using Standard Deviational Ellipse

Clayey soil is an essential component of waste containment systems. The orientation of soil particles relative to gradients of heat, hydraulic pressure and stress is a significant factor as regards the stability and hydraulic conductivity of waste containment barriers. In this paper, an analytical method called Standard Deviational Ellipse Method, which is often used for point set distribution analysis in Geographical Information System (GIS), is used to analyze particle orientation quantitatively. Through the conversion and processing of soil microstructural images, the orientation angles of soil particles are herein determined and correlated spatially across planar cross-sections. This methodology is demonstrated for a selected SEM image of a clayey soil of 0.558 porosity. The results show that the predominant orientation angle of soil particle averages is 13.445° with an anisotropic ratio of 11.49°. These results indicate that the soil sample is mostly isotropic.