Measurement of Surface Roughness of Rock Discontinuities
Rock Engineering 2009 - Rock Engineering in Difficult Conditions
Roughness of a discontinuity may be an important factor influencing shear strength of the discontinuity. Determining the roughness of a discontinuity surface and providing a numerical measure of the roughness has required traditionally considerable effort or specialised equipment. The development of new 3D imaging tools that are easy to use has provided effective fast and accurate means of creating 3D surface models from which roughness measurements can be readily obtained. These new techniques are versatile enough to enable a user to measure roughness along any desired profile and at any resolution up to the limit of the spatial subtense of an image pixel on the discontinuity surface. This paper reviews extensions to the use of 3D imaging that enable the measurement of roughness and provides some examples of the measurements. The paper also examines some of the issues associated with extracting measures from the spatial data that will support estimation of shear strength.