Application and limitations of ground-based laser scanning in rock slope characterization

Abstract

The ability of laser scanners to rapidly provide structural data in high inaccessible rock slopes has been frequently and correctly documented as an important advantage of the technique. Researchers have also shown the potential for characterizing varied rock mass characteristics including discontinuity orientation, spacing, persistence and roughness. In this paper, the authors, using laser scans of several rock slopes, illustrate the limitations and bias in structural data collection that must be allowed for. Orientation bias can occur both horizontally (laser plan angle bias) and vertically (laser elevation bias). It is suggested that the elevation angle of the laser scanner may produce point clouds that, when processed to derive structural data, may at best underestimate or even completely miss critical joint sets. Censoring can result in underestimating discontinuity size. Limitations related to rock mass reflectivity and textures are also highlighted. © 2007 Taylor & Francis Group.