Analytical formulas of anisotropic equivalent elastic parameters are established by using mechanical method of complex material. An example is made to show the feasibility and efficiency of the analytical formulas. Meanwhile

the coordinate transformation and jointed factor of regular jointed rock mass are considered. The rules of equivalent elastic parameters of regular jointed rock mass are studied. Variation rules of equivalent elastic parameters under different jointed factors are analyzed. Combining with the properties of columnar jointed rock mass in Baihetan dam site

the anisotropic characteristics and values of elastic parameters are analyzed. The results show that the jointed rock mass can degenerate into isotropic medium when the stiffness is equal; and the calculated values by using the method in the paper are well in accord with the test results in the dam site. The cylinder deflection has more effect on the equivalent elastic parameters. The results also show that after deflection

the horizontal elastic modulus and vertical modulus are reduced by 54% and 17% respectively. According to the curves

the higher the angle of cylinder

the greater reduction the elastic modulus would have. This change rule of equivalent elastic parameters revealed obvious anisotropic property of columnar jointed rock mass.