Abstract: Analysis of response of level ground subjected to earthquake is one of the most active research areas in geotechnical earthquake engineering. In this paper, seismic response including propagation of acceleration, development of pore pressure, lateral displacement and settlement, of a level ground consisting of 15 m saturated sand is analyzed, by using the finite element procedure SUMDES 2006, incorporating a critical state constitutive model for sand. Effects of model parameters on seismic ground response are studied by adjusting the values of parameter by 10 %. The analytical results show that, among these parameters, the critical state stress ratio M and , the intercept of the critical state line on the axis in the e - plane, impose stronger effect. Therefore, the accuracy of the two parameters should be secured when the parameters are calibrated against the experimental data. The results also imply that the number of parameter in the model may be reduced when it is applied to the analysis of seismic response of level ground.

Key words: free ground, seismic response, fully coupled, constitutive model, model parameters