The Influence of Shear- and Strain-Induced Changes in Surface Topography on Interface StrengthEPA Grant Number: U915318
Title: The Influence of Shear- and Strain-Induced Changes in Surface Topography on Interface Strength
Investigators: Zettler, Tamara E.
Institution: Duke University
EPA Project Officer: Jones, Brandon
Project Period: September 1, 1998 through September 1, 2000
Project Amount: $53,838
RFA: STAR Graduate Fellowships (1998) RFA Text | Recipients Lists
Research Category: Fellowship - Environmental Engineering , Engineering and Environmental Chemistry , Academic Fellowships
The objective of this research project is to develop a comprehensive understanding of both shear- and strain-induced changes in the surface topography of geomembranes and the subsequent influence on interface strength. The results will aid in the design of numerous geosynthetic applications, including landfill liner and cover systems.
The roughness of a geomembrane is a critical parameter in interface strength development. Previous research has shown that the strength mechanism for smooth geomembranes and granular soils is a function of sliding and plowing of the particles at the interface. This research quantitatively investigates the increase in roughness of the membrane as a function of various normal loads and particle angularities. The amount of plowing directly impacts the interface strength. In addition, the research will study the contact properties of the individual particles, as well as an assemblage of particles with the geomembrane to fully comprehend the plowing process. Further investigation will be conducted to determine the change in roughness of geomembranes that are subjected to strains comparable to those experienced under normal field-operating conditions. When the geomembranes are strained, it is hypothesized that rough membranes initially will show a significant decrease in roughness. As a result, the interface strength will be less than anticipated.