自由膨胀率试验的影响因素

Influential factors on free swell test

自由膨胀率是反映黏性土的膨胀性的指标之一,对判别膨胀土有较大参考价值。由于试验所需仪器设备简单,操作简便,自由膨胀率试验是目前国内测定黏性土胀缩特性时采用较多的试验项目,但因我国现行土工试验方法标准和行业规程对自由膨胀率试验方法的一些细节的规定和说明存在不足之处,使得试验人员即使完全按标准和规程规定的方法对同一土样进行试验,也很容易出现试验结果相差较大的现象。为使自由膨胀率试验方法更完善,试验结果更稳定,分析了影响试验结果的两个主要人为因素,并针对现行的标准和规程中存在的不足提出了改进建议。

Free swell is one of indexes in representing the expansibility of clayey soil and makes great valuable reference in the judgment of expansive soil. Free swell test is commonly used in China to obtain the swell-shrinking property of clay due to its simple equipments and easy operation. But, the deficiencies of standard for soil test method and trade specification exit in the regulation and explanation of the details for free swell test, that leads to the great difference in the test results when totally operating according to methods in the standards and specifications for the same soil sample. In order to make free swell test more complete and test result more stable, two main artificial factors related to test result are discussed and analyzed and some suggestions for improving the current standards and specifications are given.