From the united constitutive law of geo-material elastoplastic model

the problem of model identification among one model type is transformed to a problem of parameter identification. So

using the new bionics algorithm

immune evolutionary programming (IEP)

proposed by authors recently

the elastoplastic model identification among one model type is studied; and a new model identification method is proposed. At last

this method is verified by a numerical example. The results show that this method can get the suitable geo-material model when only displacements are known.