Experimental analysis of self-affine fractured rock surfaces through shadow length measurements

摘要: Abstract Geometrical properties of fractured basalt and sandstone surfaces are studied by measuring the length distribution shadows appearing under grazing illumination. For self-affine surfaces, is predicted to follow a power law shadow with an exponent depending only on upper cut-off related incidence angle amplitude roughness. A local thresholding procedure described allows detect small inside large illuminated zones light patches surrounded dark regions. The dependence threshold value criterion, based total zones, for optimizing these parameters introduced. both samples, exponents obtained from distributions verifying criterion in agreement theoretical expectations using classical profilometry results. Limitations lowest usable values due deviations surface characteristics discussed possible determination roughness characterization parameter evaluated.