Static Stresses by Linear and Nonlinear Methods

A nonlinear incremental loading finite element analysis is the best currently available method for calculating the static stresses in earth embankments, and is virtually the only available method for calculating static deformations. However, if deformations are not required, the static stresses may be calculated by a simpler gravity-turn-on linear elastic finite element analysis. Examples are presented of four dams, each with several different loading conditions, in which stresses were calculated by linear and by nonlinear finite element procedures. The results from both methods were in close agreement. The calculated stresses were virtually independent of the Young's modulus parameters, except within the narrow cores of zone dams. The horizontal shear and normal stresses were strongly influenced by the selected values of Poisson's ratio. However, if consistent values were used, the linear and the nonlinear analyses gave almost identical results. Recognition of the reliability of linear methods can lead to substantial savings.