Based on the Davidenkov and Matasovic skeleton curves with the irregular and unloading stress-strain hysteresis loops

two-dimensional nonlinear seismic response of two soil profiles in Suzhou quaternary sedimentary soils is studied using numerical simulation.The results show that:（1）the surface peak ground acceleration（PGA）obtained by the Matasovic model is slightly higher than that obtained by the Davidenkov model.However

ground motion durations calculated by the Matasovic model is slightly less than those obtained by the Davidenkov model.The relative difference values of surface PGA calculated by two models increases with increasing PGA of bedrock motion

which is related to the horizontal inhomogeneity of in-situ soils.（2）The shape of surface ground acceleration response spectrum is similar

and the difference of surface spectrum ground acceleration increases with increasing PGA of bedrock motion.The predominant period of surface ground acceleration response spectrum under far-field seismic motion increases with increasing PGA of bedrock motion.（3）The peak acceleration obtained by two constitutive models is fairly consistent with respect to the soil depth and lateral spatial variation

and the surface PGA under far-field seismic motions is significantly larger than that under the near-field seismic motions.