盐分浸析对我国海相沉积土物理性质的影响
Effects of salt leaching on physical properties of marine clays in China

为了研究盐分浸析对我国海相沉积黏土劣化性状的影响,分别采用NaCl溶液和蒸馏水来改变温州黏土和连云港黏土孔隙水溶液盐分浓度.测定土体的界限含水率、活性指数等物理指标,分析我国海相沉积黏土物理性状随孔隙水溶液盐分浓度的变化规律.研究结果表明,土体液限和活性指数随着孔隙水溶液盐分浓度的降低而减小,塑限几乎不变,液性指数增加.物理性质随孔隙水溶液盐分浓度的变化曲线存在一阀值浓度4.1 g/L;当孔隙水溶液盐分浓度小于4.1 g/L时,液限和活性指数急剧减小,且液限减小率为1.6~2.3,液性指数大于1.0;当孔隙水溶液盐分浓度大于4.1 g/L时,液限减小率显著降低,仅为0.2~0.8.
To investigate the effects of salt leaching on the degradation of natural sedimented marine clay’s properties in China, the pore salt concentrations of Wenzhou clay and Lianyungang clay were changed by using NaCl solution and distilled water respectively. The physical indexes such as Atterberg limits, activity and so on were measured to study the variation rules of the physical properties of marine clays affected by salt leaching. The results show that the liquid limit and activity decrease and the liquidity index increases with the decrease of the pore salt concentration, while the plastic limit is almost unchanged. The variation curves of the physical properties during salt leaching indicate a threshold concentration 4.1 g/L. When the pore salt concentration is lower than 4.1 g/L, the liquid limit and the activity index decreases drastically. The decreasing rate of the liquid limit is 1.6 to 2.3, and the liquidity index is larger than 1.0. When the pore water salinity is larger than 4.1 g/L, the decreasing rate of the liquid limit decreases to 0.2 to 0.8