Most of the constitutive model for liquefaction analysis cannot simulate the large post-liquefaction deformation of saturated sand

and there is little research on the nonlinear time-domain large deformation constitutive relationships suitable for seismic response analysis of saturated sand sites. In this paper

a feasible

simple and applicable large deformation constitutive model for time domain analysis is proposed through experimental analysis and theoretical research. The post-liquefaction stress-strain relationships of liquefied sand are obtained based on the undrained cyclic triaxial test data

then loading-reloading rules of large post-liquefaction deformation are proposed. Combined with the effective stress constitutive model based on logarithmic skeleton curve

a constitutive model that can quantitatively describe the large deformation of saturated sand liquefaction is proposed. According to the test results

the constitutive model can simulate small to large deformations from the pre-to post-liquefaction regime of sand. This constitutive model is also implemented to the program Soilresp1D for the dynamic response analysis of liquefiable soil sites. The results show that the time domain nonlinear large deformation unified constitutive model based on the logarithmic dynamic skeleton curve

effective stress-modified logarithmic dynamic skeleton constitutive model and liquefaction large deformation constitutive model can be directly applied to the dynamic response analysis of saturated sand.