Nonlinear analysis of rock-fill dams to non-stationary excitation by the stochastic Wilson-θ method

The objective of this investigation is to predict the nonlinear response of a rock-fill dam subjected to non-stationary excitation by using the finite element method in conjunction with the equivalent linearization approach. The nonlinear behavior is based on the equivalent linear method which considers the nonlinear variation of soil shear moduli and damping as a function of shear strain. Linear and non-linear analyses are performed by the stochastic Wilson-θ method. Nonlinear response of a rock-fill dam disturbed by non-stationary random excitations is compared with the linear analysis. Meanwhile, some statistical responses obtained by the linear and nonlinear analyses are checked by the Monte Carlo simulation technique. Finally, the effect of deconvolution ground motion on the nonlinear response of dam-foundation system is investigated in this paper. Two different earthquake input mechanisms are used in the dynamic analysis: the standard rigid-base input and the deconvolved-base-rock input models.