湿陷性黄土变形的微结构突变模型研究

Research on microstructural catastrophe model of deformation of collapsible loess

根据湿陷性黄土的湿陷特点,分析了其主要影响因素,包括外部因素:水、荷载与内部因素微结构及其力学性质。从湿陷性黄土的湿陷性影响出发,建立了湿陷性黄土结构失稳突变模型,并从模型基本假定、微结构模型应力特性和湿化于微结构失稳的突变关系3个方面进行了理论分析研究,在一定程度上揭示出湿陷性黄土变形机制和规律。通过微结构突变失稳理论发现:当应力状态满足孔隙微结构失稳判别式时,微结构元的变形状态将诱发微结构失稳崩塌。微结构的稳定性与结构刚度K和受力状态(σ,τ)密切相关。地下水不仅改变了颗粒的受力情况,更重要的是使颗粒间连接刚度降低,从而导致微结构失稳。

According to the characteristics of loess subsidence, the external factors such as water content and load and internal factors such as microstructure and mechanics features are analyzed. Deformation mechanism of loess subsidence is deeply researched according to the theory of microstructure un-stability. It is found that the primary causes of loess subsidence are changes of forces on the microstructure and water content after soaking, Through the analysis, it is discovered that steadily of microstructure model has enormous relatedness with the stiffness K and force state （σ,τ） of the model .When the connection rigidity reduces, the structure loses its steadily.