Soft soil deformation is not only related to the stress state, but is also related to time and exhibits viscoelastic– plastic characteristics. The generalized Nishihara model was developed from 1D state into 3D state and the viscoplastic soft matrix based on the Drucker–Prager yield model and the viscoelastic soft matrix of 2D and 3D units were established using the incremental finite element method. On the basis of the aforementioned model and matrices, a program for the soft soil adhesion elastoplastic constitutive model was developed using...