中文摘要：

高饱和度的非饱和土中由于气体处于封闭状态,其内部气压的变化必将对土体的行为产生影响。首先,对高饱和度非饱和土特性进行探讨和研究,随后,在已有非饱和土模型框架基础上,采用广义有效应力原理,建立一个适用于高饱和度条件下的非饱和土的弹塑性本构模型。模型中引入气相耗散的影响,在硬化方程中考虑封闭气体压力改变的影响。最后,利用已有的试验结果来对模型进行验证,并将模型预测结果与前人模型进行对比,表明模型预测可以很好地预测土体的行为,尤其是在高饱和度条件下其结果比其他模型更加接近实际情况。

英文摘要：

In unsaturated soils with high saturation, gas phase is disconnected, and the occluded gas pressure may change and affect the soil behavior. The properties of unsaturated soils with high saturation are first discussed; and then a constitutive model is developed within an existing constitutive framework of unsaturated soils by using the principle of generalized effective stress. This model takes into account the effect of gas diffusion, with a hardening law accounting for the effect of occluded gas pressure change. To validate the new model, the modeling results are compared with the experimental results available in the literature and the simulated results of existing models. It is shown that this model performs better than existing models, especially for the unsaturated soils at high saturation.