膨胀性非饱和土的双尺度毛细–弹塑性变形耦合模型

Constitutive modeling with double-scale pore structure for coupling of capillary hysteresis and stress–strain behaviours in unsaturated expansive soils

从宏观和微观角度,在已有的膨胀性非饱和土的双尺度本构模型BExM和湿陷性非饱和土的毛细–弹塑性变形耦合模型的基础上,发展和建立了一个可预测膨胀性非饱和土的毛细滞回和力学行为耦合的双尺度本构模型。模型考虑了土体微观结构的体变及其对宏观结构行为的影响,以及毛细和力学行为之间的耦合作用。对已有的膨胀性非饱和土的常净应力下吸力循环试验进行预测,预测结果表明该模型能够定量地描述膨胀性非饱和土的毛细和力学行为。

A constitutive model with the double-scale pore structure from macroscopic and microscopic views is proposed for predicting the capillary hysteresis and mechanical behaviours of unsaturated expansive soils based on the BExM and the existing hydro-mechanical models for unsaturated non-expansive soils.The proposed model takes into consideration two factors： the interaction between the micro-and macro-structure of expansive soils,and the fully coupled capillary hysteresis with mechanical behaviours.The predictions are performed on the cyclical controlled-suction test results published in public.The comparisons between the measured and predicted results indicate that the proposed model can quantitatively predict the capillary and mechanical behaviours of unsaturated expansive soils.