Qualitative assessment of surface roughness of limestone specimens from the orientation of unwrapped triangulated point clouds

Document Type

Conference Proceeding

Publication Date



Weathering reduces both the strength and stiffness of rock. Since weathering is a surface phenomenon it can be assessed using surface imaging techniques. The surface roughness of twelve cylindrical limestone specimens from Florida were assessed using analysis of close-range photogrammetry. Dense point clouds produced from the specimens were unwrapped and triangulated using Delaunay triangulation. Outward normal facing vectors were computed for each triangle and the γ-values were assessed. Smooth surfaces had lower average γ-values and lower standard deviations than rough surfaces. Surface roughness could easily be distinguished using lognormal probability density functions based on average and standard deviation of the γ-values. For smooth specimens, histograms of γ-values were similar to the probability density functions. However, for rough specimens the histograms of γ-values were not similar to the probability density functions. The histograms for the roughest specimens showed a bimodal distribution of values with peaks at both the low and high ends of the histograms.

Publication Title

Conference Proceedings - IEEE SOUTHEASTCON

Digital Object Identifier (DOI)