Dynamic finite element analysis of ground response using a simplified and complex soil model

This In this paper, the author conducts a three-dimensional nonlinear dynamic analysis to simulate dynamic centrifuge model tests of loose and dense soils using two different soil models that is modified Drager-Prager model and kinematic subloading tij sand model. Modified Drager-Prager model is a simple soil model that requires only 5 parameters, which can be obtained from SPT-N value, and on the other hand, the tij model is a more complex model that requires 9 parameters, which needs to be determined in the laboratory. The dynamic behavior of grounds in the model tests are consisted of Toyoura standard sand with density 1.58 g/cm³ and 1.43 g/cm³ are numerically simulated and compared with the physical models. The results show that both numerical models overestimate the peak value of the response acceleration over the physical model. The response acceleration obtained by this simplified model shows a good agreement with the one by tij model before the peak wave. The differences of the results between two numerical models become obvious after the peak wave. And the simplified model can be applied for estimating maximum seismic responses for engineering purpose. The soil behavior, however, needs to examined by a more complex model.