Salt solutions have complex effects on the swelling characteristics of compacted bentonite; these effects are caused by the inhibitory action of salinity and the ion-exchange reaction between the solution and bentonite. In order to characterize the swelling properties of compacted bentonite in a salt solution, swelling deformation tests were carried out for Gao-Miao-Zi (GMZ) bentonite specimens in NaCl and CaCl2 solutions. Swelling characteristics decreased with increasing salt concentration. Swelling strains in NaCl solution were larger than those in CaCl2 solution, even though the ionic concentration of 1.0 mol/L (M) NaCl solution is larger than that of 0.5 M CaCl2. According to the exchangeable cations tests, cation exchange was different for specimens immersed in different salt solutions. The swelling fractal model was used to predict the swelling strains of compacted bentonite in a concentrated salt solution. In this model, the effective stress incorporating osmotic suction was applied to take the effect of salinity into consideration, and the swelling coefficient, K, was employed to describe the swelling properties affected by the variation in exchangeable cations. In the model, fractal dimension was measured by nitrogen adsorption, and the salt solution had little effect on fractal dimension. K was estimated by the diffuse double layer (DDL) model for osmotic swelling in distilled water. Comparison of fractal model estimations with experimental data demonstrated that the new model performed well in predicting swelling characteristics affected by a salt solution.

中文翻译：

---

含离子交换反应的压实GMZ膨润土在盐溶液中溶胀特性的预测

盐溶液对压实膨润土的溶胀特性有复杂的影响；这些影响是由盐度的抑制作用以及溶液与膨润土之间的离子交换反应引起的。为了表征压实膨润土在盐溶液中的溶胀特性，对高庙子（GMZ）膨润土试样在 NaCl 和 CaCl2 溶液中进行了溶胀变形试验。溶胀特性随着盐浓度的增加而降低。尽管 1.0 mol/L (M) NaCl 溶液的离子浓度大于 0.5 M CaCl2 的离子浓度，但 NaCl 溶液中的溶胀应变大于 CaCl2 溶液中的溶胀应变。根据可交换阳离子测试，浸泡在不同盐溶液中的样品的阳离子交换是不同的。膨胀分形模型用于预测压实膨润土在浓盐溶液中的膨胀应变。在该模型中，应用结合渗透吸力的有效应力来考虑盐度的影响，并采用溶胀系数 K 来描述受可交换阳离子变化影响的溶胀特性。在模型中，分形维数是通过氮吸附来测量的，盐溶液对分形维数的影响很小。K 是通过扩散双层 (DDL) 模型估算的，用于蒸馏水中的渗透溶胀。分形模型估计与实验数据的比较表明，新模型在预测受盐溶液影响的膨胀特性方面表现良好。在该模型中，应用结合渗透吸力的有效应力来考虑盐度的影响，并采用溶胀系数 K 来描述受可交换阳离子变化影响的溶胀特性。在模型中，分形维数是通过氮吸附来测量的，盐溶液对分形维数的影响很小。K 是通过扩散双层 (DDL) 模型估算的，用于蒸馏水中的渗透溶胀。分形模型估计与实验数据的比较表明，新模型在预测受盐溶液影响的膨胀特性方面表现良好。在该模型中，应用结合渗透吸力的有效应力来考虑盐度的影响，并采用溶胀系数 K 来描述受可交换阳离子变化影响的溶胀特性。在模型中，分形维数是通过氮吸附来测量的，盐溶液对分形维数的影响很小。K 是通过扩散双层 (DDL) 模型估算的，用于蒸馏水中的渗透溶胀。分形模型估计与实验数据的比较表明，新模型在预测受盐溶液影响的膨胀特性方面表现良好。用于描述受可交换阳离子变化影响的溶胀性能。在模型中，分形维数是通过氮吸附来测量的，盐溶液对分形维数的影响很小。K 是通过扩散双层 (DDL) 模型估算的，用于蒸馏水中的渗透溶胀。分形模型估计与实验数据的比较表明，新模型在预测受盐溶液影响的膨胀特性方面表现良好。用于描述受可交换阳离子变化影响的溶胀性能。在模型中，分形维数是通过氮吸附来测量的，盐溶液对分形维数的影响很小。K 是通过扩散双层 (DDL) 模型估算的，用于蒸馏水中的渗透溶胀。分形模型估计与实验数据的比较表明，新模型在预测受盐溶液影响的膨胀特性方面表现良好。