Abstract: In order to obtain geometric information of rock mass discontinuities rapidly and comprehensively to improve stability evaluation quality, a series of solution models，3D trace model, 2D trace model of random projection plane and the orientation solution model with detailed criterion were put forward and established under the theories of spatial geometry, azimuth conception and projection transformation on the basis of obtaining spatial coordinates of discontinuities through digital close range photogrammetric technology. In the first place, more detailed information about trace distribution status could be displayed through 3D trace model, and in the second place, trace information of any important projection plane could be obtained through 2D trace model, therefore, its physical significance was highlighted. In addition, orientation obtaining precision based on orientation solution model was discussed through the theory of error. The experimental results demonstrated that the problem of orientation obtaining of approximate linear discontinuities could be solved when position measurement error was less than 2 cm on slope 3D model established by digital close range photogrammetry. On the whole, more abundant, detailed and comprehensive discontinuity information could be obtained and applied to the stability analysis and evaluation with the combination of digital close range photogrammetry and geometric information solution models of rock mass discontinuities.

Key words: discontinuities, trace, orientation, digital close range photogrammetry