Abstract: In order to investigate the effect of seawater salinity on such essential characteristics as liquid and plastic limits,plasticity index, and particle size distribution,the liquid and plastic limits of clay minerals under different sodium chloride concentrations and in different soaking durations were measured and the grain size analysis tests of clay minerals with different sodium chloride concentrations were also conducted. The results indicate that the salinity influences greatly liquid and plastic limits of montmorillonite. The liquid and plastic limits decrease with the increase of salinity, and such decreasing trend slows down. Compared with montmorillonite, less salinity effects on kaolinite and illite are found. With certain salinity different soaking durations have little impact on the essential characteristics of clay minerals.The grain size analysis tests show considerable reduction of clay content of montmorillonite with different salinity and small reduction of clay content of kaolinite and illite and the invisible effect of saline solution on fine particle concention in kaolinite and illite.

Key words: geotechnical engineering, clay mineral, sodium chloride solution, liquid and plastic limits, particle size distribution

摘要： 为研究海水盐度对黏土矿物的基本特性包括液限、塑限、塑性指数和颗粒级配的影响，测量了黏土矿物在不同浓度NaCl溶液中和不同浸泡时间下的液塑限，并进行了不同浓度NaCl溶液中的黏土矿物的颗分试验。结果表明：盐度对蒙脱土的液塑限影响非常显著，随着盐度增加，液塑限降低，并且降低的趋势变缓；与蒙脱土相比，盐度对伊利土和高岭土的液塑限的影响较小；当盐度一定时，不同的浸泡时间对黏土矿物的基本特性的影响很小；颗分试验显示不同盐度下蒙脱土的黏粒含量减小显著，高岭土和伊利土黏粒含量降低较小，表明NaCl溶液使蒙脱土土中细颗粒产生凝聚效果显著，而盐溶液对高岭土和伊利土中的细颗粒凝聚效果不明显。

关键词: 岩土工程, 黏土矿物, NaCl溶液, 液塑限, 颗粒级配