MODELING OF THE NONLINEAR DYNAMIC BEHAVIOR OF REINFORCED SLOPES IN SANDY SOILS

In this paper, the nonlinear dynamic behavior of geogrid-slope system using 2D finite element analyses is studied. Comparative analyses of seismic response by different numerical approaches are presented. One dimensional equivalent linear visco-elastic analysis performed in the frequency domain is used to evaluate the Rayleigh damping coefficients to perform the finite element analyses for 1D and 2D nonlinear analyses. The influences of distance to the first layer of geogrid and the number of reinforcement layers on the dynamic behavior of slope are investigated. The effect of type of bed rock on the numerical results is also investigated and the results are compared to each other in order to clarify the effect of bedrock on soil behavior under earthquake excitations. The results show underestimation of the peak ground acceleration for nonlinear analysis compared to the equivalent linear visco-elastic analysis for deep depths and overestimation values for shallow depths. The results indicate that the presence of geogrid layers yield higher horizontal acceleration and play a significant role on the decrement of slope settlement.