Two-Dimensional Characterization of Topographies of Geomaterial Particles and Surfaces

Abstract

The soil-structure interface is fundamental to the performance of many geotechnical engineering systems; including penetration test devices, deep foundations, and retaining structures. In geotechnical engineering structures, the counterface may range from a polymer in the case of a geosynthetically reinforced earth retaining structure to steel for cone penetration testing or pile foundations. Interface strength is affected by many factors, among which surface roughness is the most dominant. To date common practice has been to characterize counterface surface roughness by a roughness parameter based on only its spatial properties and soil roughness separately by various incompatible means resulting in two roughness values unrelated to each other. The vast number of analyzing methods and developed parameters reveal the general confusion regarding this concept.

Rather than analyzing the particulate and continuum media separately, it is compulsory to coalesce the analysis and quantify the relative nature of interface behavior. This can be accomplished by examining the particulate and continuum media through the same powerful tools.

The motive of this study is to develop a unified approach to determining the index properties of particles and surfaces in a particle-surface interface. This is accomplished by examining several particle shape and surface roughness parameters in terms of their ability to uniquely describe and distinguish particulate medium and continuum roughness, respectively. In this study, surfaces are analyzed as derived particles by wrapping surface profiles and particles are evaluated as derived surfaces via unrolling particle outlines. In addition, particle shape parameters are modified to allow surface roughness analysis and surface roughness parameters are modified to characterize particle shape. A unified approach for particulate shape and continuum roughness would ultimately lead to a better understanding of micro-scale interaction mechanism and better quantification of macro-scale mobilized resistance for soil and engineering surface interaction.