Abstract E8g Xa-hv
The collection of geomechanical data in the mining industry is often hindered by limited access to rock exposures. Consequently, 4Gs#_|!
there is a need for a tool that permits fast and safe acquisition of information that best characterizes a geological structural regime. yQE|FbiA
This paper presents a digital face mapping methodology used to construct discontinuity trace maps from photographs of rock faces. eznt "Rr2
The method is applicable under a range of ground conditions, while at the same time trying to keep user intervention to a minimum. O*{<{3
The developed procedure uses a series of photographs of a rock face taken under symmetrical lighting orientations. All digitized lo* OmAF
pictures are then introduced into the developed software, where pre-processing optimizes subsequent analysis. Discontinuity traces AE`X4 q
are then extracted from the enhanced images using edge and line detection algorithms. This results in a binary image where black *,<A[XP
pixels correspond to the detected features. The nature of these features is identified using artificial neural networks, specifically 0"7%*n."2
trained for this application. As a result, it is possible to distinguish between segments in the image that are due to the presence of a CsHHJgx
discontinuity and those due to other phenomena. This classification process provides a series of binary images that represent I Wcgh`8
discontinuity traces in the area of interest. These images are superposed and merged. All processes described above are fully n2&*5m&$
automatic. In order to complete the process, the system operator ensures that incomplete discontinuity segments are reconstructed. -SZX UN
Following this, a discontinuity trace map is constructed and the discontinuity network is characterized using geomechanical criteria. yG\ ^PD
The methodology to construct discontinuity trace maps is illustrated using an example from a rock exposure in an underground >p#` %S
mine. Subsequently the methodology is implemented in two case studies from underground mines and one in a quarry. These case DhZuQpH
studies represent different geological and lighting conditions. This information is then used to successfully characterize the wBZ=IMDu\
investigated rock masses. Present limitations of the method are also identified. zWKnkIit,
r 2003 Elsevier Ltd. All rights reserved.
