Joint roughness directly affects the behaviour of discontinuities at the laboratory scale and the rockmass at excavation scales. As large infrastructure projects (e.g. deep base tunnels for transportation, large open pit and underground mines with complex geometries, and deep geological repositories for the storage of nuclear waste with unprecedented design life spans) are being constructed in more challenging environments, the need for sound understanding of the geomechanical behaviour of rock joints and in turn the roughness of joint surfaces is paramount. This paper presents practical methods for the analysis of joint surface roughness from three-dimensional Structure-from-Motion (SfM) photogrammetry models and two-dimensional cylindrical core scan photographs. In order to understand the variability of joint roughness on the surface of a discontinuity through drill core, hundreds of profiles were measured with JRC values calculated for each profile. Through this process, the variability of JRC values based on two-dimensional profiles across a surface is highlighted. Finally the effectiveness of cylindrical core scans is evaluated by comparing the roughness estimates to scanlines taken across the surface of the discontinuity.

This content is only available via PDF.
You can access this article if you purchase or spend a download.