Abstract: On the basis of the theory of thin arch dam’s buckling instability, the nonlinear buckling of shallow arch is introduced into the calculation of horizontal arch ring’s buckling for arch dam. The nonlinear functional relationship between the maximum flexibility coefficient and the dam height is obtained by simplifying quantitative calculation and analysis. Furthermore, according to the parameters of built arch dam at home and abroad in the latest version of Hydraulic Design Manual, the empirical formula of flexibility coefficient is given in consideration of the impact of dam height H, arc length-height ratio, and valley shape. Calculations for some built arch dams with this formula verified that this formula is valuable in the actual design.

Key words: buckling stability of arch dam, flexibility coefficient, arc length-height ratio, non-linear buckling