An elastoplastic constitutive model for frozen sandy soil considering particle breakage

Abstract

A series of triaxial compression tests of frozen sandy soil are carried out under five confining pressures (1 MPa, 4 MPa, 6 MPa, 8 MPa and 10 MPa) at –6 °C. By comparing the grain size distribution curves of frozen sandy soil before and after shearing, it is found that significant particle breakage can occur during triaxial shearing. Particle breakage changes internal structure of geomaterials and has a significant effect on their stress–strain relationships. In order to accurately describe the effect of particle breakage of frozen sandy soil on the stress–strain relationships, an elastoplastic constitutive model for frozen sandy soil considering particle breakage is proposed. Based on the energy balance equation established by Indraratna and Salim, the constant critical state stress ratio (M_cr) in the energy balance equation is modified to the stress ratio (M) which changed with shear strain during the shearing process. A yield function, considering particle breakage, is proposed using the modified energy balance equation. The hardening law is determined based on the rebound test results of frozen sandy soil, and the associated flow rule is adopted in the model. Compared with experimental data, the model can well simulate the stress–strain relationships under different confining pressures for frozen sandy soil.

Highlights

• The particle breakage characteristics of frozen sandy soil are studied.

• The energy balance equation considering particle breakage is modified to calculate the energy dissipation of frozen sandy soil.

• An elastoplastic constitutive model for frozen sandy soil considering particle breakage is proposed.

Keywords:

• Frozen sandy soil
• particle breakage
• energy consumption
• elastoplastic constitutive model

Disclosure statement

The authors declare that there are no conflicts of interest.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (41701063 and 41672304), and Student's Platform for Innovation and Entrepreneurs (04070308).