Automated identification and characterisation of discontinuity sets in outcropping rock masses using 3D terrestrial laser scan survey techniques

It is generally accepted that the identification and characterisation of discontinuities in discontinuous rock masses is one of the most important aspects in rock mass modelling. Traditional manual field survey methods for gathering discontinuity properties are biased, hazardous, difficult and time-consuming. This paper describes a computer approach, based on terrestrial laser scan data, which seems promising as an alternative survey technique. A terrestrial laser scanner can create rapidly, a highly accurate 3D point cloud models of any outcropping rock mass. The point cloud model can be converted into a virtual 3D surface using digital surface reconstruction. This paper describes a method using clustering algorithms, that allow for automated identification and calculation of different discontinuity sets using these virtual rock surfaces. Not only is laser scanning a safer and faster surveying technique, it also provides a more accurate, precise and reliable basis for discontinuity identification and characterisation.