两种因素对膨润土与砂混合试样胀缩变形特性的影响研究

膨润土与砂混合试样在干湿循环过程中的胀缩体变可分为可逆性和不可逆性胀缩体变两个分量。对击实膨润土与砂混合试样开展干湿循环试验,研究了应力和干湿路径(即两种因素)对体变分量及干湿循环稳定状态的影响规律:①竖向应力增加将降低可逆性体变分量增大不可逆性体变分量的累积;②可逆性体变的大小与干湿路径在饱和度空间所处的区域相关;③干湿循环幅值影响着试样的不可逆性胀缩体变的累积;④干湿循环稳定状态具有一定的路径依赖性。

Study on Effects of Two Factors on Swelling-shrinkage Deformation Characteristics of Bentonite and Sand Mixture

The swelling–shrinkage volume variation of bentonite and sand mixture in wetting-drying cycle may be divided into reversible and irreversible components. The wetting-drying test was carried out on the compacted specimens of bentonite and sand mixture to study how the stress and the wetting-drying path (i.e. two factors) affect the components and the stability of the cycle. It is concluded that, ① the increment of vertical stress may decrease the reversible component and increase the accumulation of the irreversible component; ② the reversible component relates to the location of the wetting-drying path in the saturation space; ③ the amplitude of the wetting-drying cycle affects the accumulation of irreversible component ; ④ the stability of wetting-drying cycle is of certain dependence to its path.