Abstract: The parameters of Duncan-Chang (E-B) constitutive model for the tailings dam of an Iron Mine in Chengde are obtained through soil tests. Midas GTS finite element analysis software is adopted to establish the numerical calculation model for tailings dam and to make the sensitivity analysis of E-B model parameters K，n, K_b, m on the tailings deformation respectively. The analysis results show that the K，n values greatly affect of the calculation accuracy of the tailings dam deformation. Among these values，K affects the vertical displacement of the tailings pond to be utmost，and n impacts on the horizontal displacement to be utmost. 2 reasonable parameters values are extremely important for the tailings dam deformation.

Key words: Tailing sands, Duncan-Chang model, Finite-element method, Sensitivity analysis