非饱和土毛细滞回与变形耦合弹塑性本构模型

在修正剑桥模型的基础上，提出了一个非饱和土毛细滞回与骨架变形耦合的弹塑性本构模型。该模型考虑了基质吸力与饱和度对屈服应力的影响，可以同时描述非饱和土的弹塑性变形特性与毛细循环滞回效应。根据塑性体变的产生使非饱和土进气值增大的特点，建立了变形对土-水特征曲线影响的数学描述。该模型有效地考虑了饱和度对前期屈服应力的作用，准确地反映了土体在不同土-水状态条件下（脱湿和吸湿过程）强度特性的变化，而且还可以有效地描述水力循环历史对土体变形的影响。通过与试验数据对比，证明了该模型能够模拟非饱和土的主要力学特性。

An elastoplastic constitutive model of unsaturated soils with capillary hysteresis and deformation coupling

An elastoplastic constitutive model of unsaturated soils with capillary hysteresis and skeletal deformation coupling, is developed based on the modified Cam clay model. The new model considers the effects of matric suction and saturation on the yield stress, and can be used to describe simultaneously the elastoplastic deformation and capillary hysteresis of unsaturated soils. Based on the fact that the entry air value increases with plastic volume deformation, a formulation is developed to describe the effect of deformation on the soil-water characteristic curve. The new model can account for the effect of saturation on the prophase yield stress, properly represent the difference of soil strength under different soil-water states, and effectively describe the effect of drying/wetting history on the skeletal deformation. The simulations are compared to the experimental data available in the literature. It is shown that the new model can simulate the main mechanical features of unsaturated soil behavior.