Research on extended hypoplastic model and its verification for deposits soil

Abstract

Abstract In order to illustrate the mechanical properties of the coarse-grained deposits soil, a series of large scale triaxial tests of deposits soil from the southwest region of China were carried out. Based on the test data and the basic idea of hypoplasticity, the Wu-Bauer hypoplastic model was extended to describe the mechanical behavior of the deposits soil, so that the constructed equations were induced for developed analysis. The model parameter identification method was proposed for the establishment of extended hypoplastic constitutive model by using improved differential evolution algorithm, which was targeted to find the optimization of the error function between test and theoretical results instructed by the inverse analysis principle. Then, an optimization calculation program was written to achieve the identification of the constitutive model parameters, which showed that the proposed identification method was better than the conventional method of parameter determination. Moreover, the test data and numerical calculation of one-dimensional compression test and triaxial test were compared, which indicated that the extended Wu-Bauer hypoplastic model could reflect the different mechanical properties of the deposits soil under different initial conditions.