Use of statistics as a tool to evaluate the strength between interfaces with geomembranes and other materials obtained by Conventional Direct Shear (CDS) and Inclined plane (PI) testing

University of Brasilia, Brazil

^* Corresponding author: raislagomess@gmail.com

Abstract

Understanding the behavior of interface resistance involves factors such as the friction angle of the interface, the asperity height of the geomembrane, type of soil in contact with the synthetic material, the applied stresses, among others. In this context, statistical techniques have the ability to establish correlations between variables for evaluating interface strength tests, such as conventional direct shear (CDC) and inclined plane (PI). In this study, the interfaces between sand and geomembrane (SG) were analyzed for the CDC and PI tests. The aim was to obtain a statistical understanding of the parameters that most influenced the interface friction angle (ϕint) using Pearson's correlation matrix. It was observed that the soil friction angle (ϕs) and the asperity height of the geomembrane (hG) showed the highest correlations with ϕint for the tests carried out with the SG-CDC interfaces. The results also showed that for the SG-CDC interfaces, 7.15% of the correlations showed a strong or moderate correlation, while 35.70% showed weak correlations and 50% showed very weak correlations. On the other hand, for the SG-PI interface, only hG showed a strong correlation, with 29%, 50% and 14% of the variables classified as moderate, weak and very weak, respectively.