2021 Volume 16 Issue 4 Pages 397-413
Japan Geotechnical Society has implemented proficiency tests for more than a decade. In the present report, the following two topics are focused on; homogeneity of distributed samples and validity of the evaluation methods. Regarding the former one, possible influence of changing the homogeneity criterion in JIS Z 8405 and sample preparation methods suitable for geomaterials are explained. Regarding the later one, with showing properties of the assigned values and normality of the test results, solutions for existing problems in the proficiency tests of geomaterial testing are discussed. And it is recommended that the repeating tests should be applied to the test for particle size distribution of soils.
