The image analysis of discontinuity spacings distribution in rock

Rock fractures play an important role in rock engineering. The traditional method is ill-suited the attainment of a reliable quantitative description of discontinuity geometry. The feasibility of viable means of applying DIP to the discontinuity spacings in rocks was discussed. Photogrammetric measurements can be taken from digital images which are suitable for computer processing. It may be possible to semi-automate the detection of discontinuities in digital images of rock mass exposures, If this can be achieved, a huge increase in the speed of data acquisition will be realised. The following method can be taken to measure the spacing: firstly, statistic the frenquency of orientation angle of every rock joints. Several discontinuities which the trend is pararal or nearly pararal often can be grouped using frenquency histogram. Secondly, after cluster analysis, it can be grouped according to the princple which makes the distance minimum within a group and maximum between groups. It can recorder the distance between end point and intersect along with the scanline on the computer. Thirdly, statistic the parameter of rock spacing. How to obtain the spacing parameter on the conditions that the traces is not parallel each other is explored, especially the fracture characterized as selfsimilarly.