一个高饱和度非饱和土的本构模型  

A constitutive model of unsaturated soils with high saturation

作　　者：刘艳[1,2] 韦昌富[1] 赵成刚[2] 房倩[2] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,武汉430071 [2]北京交通大学土建学院,北京100044

出　　处：《岩土力学》2013年第8期2189-2194,共6页Rock and Soil Mechanics

基　　金：中央高校基本科研业务费专项资金资助(No.2012JBM081);国家自然科学基金资助(No.51108022;No.11072255)

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。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.

关 键 词：高饱和度 封闭气体 本构模型 非饱和土 广义有效应力原理 

分 类 号：TU443[建筑科学—岩土工程]