六偏磷酸钠浓度对软黏土颗分试验的影响

The Effect of Sodium Hexametaphosphate Concentration on the Results of Grain Size Distribution Analysis for Soft Clay Samples

结合渤海近海口软基处理工程,开展了不同浓度的六偏磷酸钠溶液对渤海近海口软黏土颗粒分析试验(密度计法)的影响研究,简单阐述了六偏磷酸钠对颗分试验的影响机理。试验结果表明:六偏磷酸钠对颗粒分析试验结果有着明显影响,试验中添加六偏磷酸钠是必不可少的;渤海近海口沉积的淤泥质软黏土适宜采用浓度为6%～8%的六偏磷酸钠溶液(10mL)作为颗粒分析试验的分散剂,在此浓度区间六偏磷酸钠的分散效果最佳,有较好的稳定性。细粒含量随着添加的六偏磷酸钠浓度的增加而增大,并趋于稳定,其中粉粒含量先减小后增加,黏粒含量先增加后减小。

The influence of different concentration of sodium hexametaphosphate solutions on the laboratory grain size distribution analysis results(densitometer method)on the soft clay samples from a ground improvement project in estuary area of Bohai.The test results indicate that,the concentration of sodium hexametaphosphate solutions have a significant impact of the test results.The sodium hexametaphosphate solution should be used in the laboratory gain size distribution test.For the soft clay sample from estuary area of Bohai,the dispersion solution should use 10 ml sodium hexametaphosphate solution with a concentration between 6%and 8%.With the appropriate concentration,the test results demonstrate a good stability.The content of fine-grained group increased with the increase of sodium hexametaphosphate concentration and tended to be stable.The content of powder first decreased and then increased,and the content of clay first increased and then decreased.