Quantitative Characterization Method for Rock Surface Roughness with Different Scale Fluctuation

Quantitative characterization of the surface roughness plays a vital role in the field of rock mechanics. The objectives of this study were to propose a new index that can describe the various morphological characteristics with different scale fluctuation. The power spectral density (PSD) parameters and conventional statistical parameters were used to analyze the roughness of meso-scale grind surfaces, intermediate-scale synthesis surfaces, and macro-scale shear surfaces. The results showed that the PSD parameters (slope k, intercept b, spectral moment lambda(0), and spectral shape parameters omega(1) and omega(2)) and conventional statistical parameters (RMS and Z(2)) have evident uniqueness and uniformity in characterizing the roughness with different scale fluctuation. It is necessary to appropriately use the correct parameters for classifying and quantifying the roughness. For this purpose, a new characterization index SLA was proposed based on the spectral shape parameter omega(1), spectral moment lambda(0), slope k, and angle fractal index C.