排气状态对非饱和土变形特性的影响

为研究排气状态对非饱和土固相、液相和气相的分布影响,以排气状态为控制变量,通过不同饱和度、不同干密度的非饱和粘土和粉土的三轴剪切试验,分析了气相对非饱和土变形特性的影响。结果表明,试验过程中非饱和土表现出了明显的剪胀性,不同排气状态下的剪胀程度不同,且排气状态对粘土变形的影响较粉土显著。通过微观机理解释为试验过程中孔隙气压力的增大程度不同,会造成土体颗粒间不平衡力矩的差异性,从而导致剪胀程度的不同。

Influence of Exhaust Condition on Deformation Characteristic of Unsaturated Soil

To study the influence of exhaust condition on the distribution of the solid phase, liquid phase and gas phase, taking exhaust condition as the control variable, the influence of gas phase on the deformation characteristics of unsaturated soils is analyzed through triaxial shear test of unsaturated clay and silt with different saturation and dry density. The results show that unsaturated soil appears obvious shear dilatation in the process of experiment; the degree of shear dilatation is different under the different exhaust conditions; clay exhibits more obvious deformation than silt under exhaust condition. The microscopic mechanism explained by the difference of unbalanced moment between soil particles leads to different degrees of shear dilatation owing to the different varying degrees of pore air pressure in experimental process.