Identification method for nonlinear constitutive model of soft rock

Based on P.Perzyna equation,which is the general nonlinear rheological constitutive equation for geotechnical material,the paper develops the FEM computation program EVP2D for the identification purpose.The program computation combining the uniform design method produces a number of effective overall input output data,which contain a great deal of constitutive information and could be used to train the ANN identification model.Then an ANN model is designed based on the practical measuring displacements for the rheological constitutive model identification of the surrounding rockmass and a program CYJBS3.M for its training and identifying algorithm is also developed on the base of MATLAB software.A real application example shows that the UD-FEM-ANN identification method is successful and executive by performing its whole computation from the uniform design of the identified constitutive parameters of the surrounding rock rheological model,the FEM computation of the training data to the training and identification of the ANN model.