非饱和原状土本构模型研究  

A Study on Constitutive Model of Unsaturated Natural Soils

作　　者：金旭[1] 赵成刚[1] 

机构地区：[1]北京交通大学土木建筑学院,北京100044

出　　处：《北京工业大学学报》2011年第1期85-91,共7页Journal of Beijing University of Technology

基　　金：国家'九七三'计划资助项目(2010CB732100);国家自然科学基金资助项目(50778013);北京市自然基金资助项目(8082020)

摘　　要：提出了反映外力和浸润2个扰动因素影响的耦合扰动变量的概念.根据复合材料均匀化理论的思想建立了适用于非饱和结构性土的本构模型,该模型中考虑了水的滞后性与土体变形的耦合作用及饱和度变化对结构性劣化的影响,同时给出了耦合扰动变量的演化方程.将本文模型的预测结果与已有的实验结果进行了对比,本文模型能较好地反映非饱和原状土结构性对土体力学性能的影响,即软化现象.A new expression form of coupled disturbing variable for unsaturated soils is defined in this paper, in which both of disturbance factors that external force and wetting are reflected. Moreover, a new constitutive model of unsaturated natural soils is build up in accordance with homogenization theory for composites materials. In the model, the coupling of hydraulic hysteresis and stress-strain behavior in unsaturated natural soils and the influence of saturation change on soil structure degradation are considered, and the evolution equation of coupled disturbing variable is presented. Comparing the calculation results of the new model with the experimental results, it can be seen clearly that the new model is satisfactory in describing the influence of soil structure degradation on the mechanical properties of unsaturated natural soils that is strain-softening behaviour.

关 键 词：扰动变量 非饱和土 结构性 劣化 模型 

分 类 号：TU441[建筑科学—岩土工程]