软土有机质含量测定方法对比分析

Comparative Analysis of Determination Methods for Organic Matter Content in Soft Soil

摘要:

有机质是土壤的重要组成部分,其含量对土体工程稳定性和土样定名影响显著。为深入了解有机质含量不同测定方法的适用性和局限性,采用灼失量法(550 ℃、700 ℃和950 ℃)和重铬酸钾容量法对各软土样的有机质含量进行测定,并对测定结果进行对比分析。结果表明:重铬酸钾容量法测定的有机质含量小于灼失量法,两种方法的测定结果具有较好的线性相关性,相关性系数为0.915 9。灼失量法测定的有机质含量随灼烧使用温度的升高而逐渐增大;对于软土等高有机质含量土体,在进行有机质含量测定时,推荐采用灼失量法(550 ℃)进行。

Abstract:

Organic matter is an important component of soil, and its content has a significant impact on the engineering stability and classification of soil mass. To further explore the applicability and limitations of different determination methods for organic matter content, the ignition loss method (550 ℃, 700 ℃ and 950 ℃) and potassium dichromate volumetric method were adopted to test the organic matter content of soft soil samples, and the measured results were compared and analyzed. The results indicate that the organic matter content determined by the potassium dichromate volumetric method is lower than that by the ignition loss method, and there is a good linear correlation between the two methods with a correlation coefficient of 0.915 9. The organic matter content measured by the ignition loss method increases gradually with the rise of ignition temperature. For soft soil and other soil masses with high organic matter content, the ignition loss method at 550 ℃ is recommended for organic matter determination.