Abstract: This paper presents a simplified finite element method using viscoplastic strain softening mode is to capture the strain localization points in hydraulic structures, in which the bifurcation theory is adopted as the condition of onset of strain localization. The trait of this method is that the continuum elastoplastic tangent modulus needed in the bifurcation theory is just used in the judgment of localization in every time step, and has no effecton the process of viscoplasticity return mapping algorithm proposed. Compared with other methods, this model is not only based on simple theory, but also is easy to program. And numerical results show that this method is reasonable and feasible through the analysis of slope stability.

Key words: strain localization, hydraulic structures, FEM, strain softening, simplified calculation