钠基、钙基蒙脱石低含水率状态下基质势能的多元动力学研究EI北大核心CSCD

基于分子动力学和元动力学(Metadynamics)的研究方法,探索了钠基蒙脱石和钙基蒙脱石在低含水率状态下的基质吸力,建立了含水率在5%~30%的土水特征曲线,通过曲线对比发现钠基蒙脱石与钙基蒙脱石的基质吸力均随含水率的升高而指数下降,并且在含水率小于20%时,钠基蒙脱石的基质吸力略小于钙基蒙脱石,含水率大于20%后钠基蒙脱石基质吸力略大于钙基蒙脱石。得到钠基蒙脱石在5%含水率时的基质吸力约为4.2 GPa,钙基蒙脱石在5%含水率时的基质吸力约为4.4 GPa。该研究结果为众多吸力测量的实验值和理论模型提出的预测值提供了参考。

METADYNAMICS STUDY OF MATRIC POTENTIAL IN SODIUM AND CALCIUM MONTMORILLONITES UNDER LOW MOISTURE CONTENT

Based on molecular dynamics and Metadynamics, the matric potential of the sodium montmorillonite and calcium montmorillonite at low moisture content conditions are discussed. And the soil water characteristic curve is established at a moisture content range of 5% - 30%. The matric suction of sodium montmorillonite and calcium montmorillonite are found to decline exponentially with the increase of moisture content. When the moisture content is less than 20%, the matric suction of sodium montmorillonite is slightly less than calcium montmorillonite. When moisture content is more than 20%, the matric suction of sodium montmorillonite is slightly larger than that of calcium montmorillonite. The matric suction of sodium montmorillonite is about 4.2 GPa at the moisture content of 5%, and the matric suction of calcium montmorillonite is about 4.4 GPa. These methods and results provide references for suction measurements by experiment or predicted values by theoretical models.