A combined two-surface elastoplastic model for hydro-mechanical coupling behavior of unsaturated cohesive soils
LI Xiaoxuan1，2，LI Tao3
(1. Yellow River Engineering Consulting Co.，Ltd.，Zhengzhou，Henan 450003，China；2. Post-Doctoral Station of Yellow River
Engineering Consulting Co.，Ltd.，Zhengzhou，Henan 450003，China；3. School of Civil Engineering，
Beijing Jiaotong University，Beijing 100044，China)
Abstract：Complex hydro-mechanical coupling properties of unsaturated cohesive soils appear under external loading. In this paper，an elastoplastic two-surface model which can describe the hydro-mechanical coupling character has been formulated based on elastoplastic theory，adapting the suggested plastic hardening criterion extended to unsaturated soils，considering the arbitrary stress path variation in the(p?-q-s) space. The model reflects the coupling effect of stress and suction through mean skeleton stress and modified suction. Two groups of loading surfaces and bounding surfaces were used to describe the plastic yield induced by coupled hydro-mechanical during loading and/or dry-wetting processes respectively. The fully coupled description and solution of the hydro-mechanical characteristics of unsaturated clay are realized. Compared with the conventional triaxial shear test results of unsaturated clay，the model can better simulate the stress-strain characteristics of unsaturated clay under coupled hydro-mechanical.
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2023, Vol. 42 
