Abstract: This paper studies the anisotropic properties of the jointed rock mass at the inlet of the Changheba Power Station. The digital close-range photogrammetry technology was used to obtain the topographic information of the jointed surface and imported the information into the MATLAB to generate a three-dimensional jointed rock mass digital elevation model. Based on the wavelet analysis theory, the joint traces in different directions of the jointed surface are separated into the first-order large undulating traces that representing the main contour shape and the second-order small convex traces that representing the secondary roughness, and the joint roughness coefficient (JRC) of the traces was calculated and the anisotropy characteristics of different components of the jointed surface were studied. The results show that: (1) The first-order undulating part and the second-order convex part of the jointed trace have different roughness development dominant directions. (2) Both the first-order undulating trace and the second-order undulating trace of the joint surface have obvious roughness anisotropy. The results provide a basis for the study of the mechanical behavior of joint surfaces and the anisotropy of seepage behavior.

Key words: joint plane, digital close-range photogrammetry, roughness coefficient (JRC), wavelet analysis, anisotropy