A simple anisotropic bounding surface model for saturated clay considering the cyclic degradation

Abstract

A simple elastoplastic bounding surface plasticity model accounting for anisotropy and cyclic degradation of saturated clay is developed within the framework of critical state soil mechanics and the bounding surface plasticity. The associated flow rule is adopted and merely three constants more than those of the Modified Cam-Clay model are required for simplicity. A preferable rotational hardening rule is generalised into the domain of dynamic model after comparing different kinds of rotational hardening rules to describe the development of anisotropy. The radial mapping rule and the mapping origin moving with stress reversal are incorporated into the bounding surface plasticity concept to capture the behaviours of clay under cyclic loads. A new interpolation function of plastic modulus associated with the length of the accumulated deviatoric plastic strain is introduced into the model to describe the cyclic degradation. The developed model is validated by undrained monotonic and cyclic triaxial tests on isotropically and anisotropically consolidated clay. The proposed model is capable of reproducing the stress–strain behaviours of saturated clay, and capturing the anisotropy and cyclic degradation.

KEYWORDS:

• Saturated clay
• anisotropy
• cyclic degradation
• rotational hardening
• bounding surface plasticity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from the National Natural Science Foundation of China (Grant No. 51678390), the Key Projects in the Tianjin Science & Technology Pillar Program (Grant No. 15JCZDJC40600) and the Fundamental Research Funds for the Universities in Tianjin city (Grant No. 2016CJ04, 2016CJ01) is gratefully acknowledged.