Accession Number : AD0433188


Title :   OPERATOR VARIANCE IN THE DETERMINATION OF THE PLASTIC LIMIT,


Corporate Author : COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H


Personal Author(s) : Ballard,G. E. ; Weeks,W. F.


Report Date : SEP 1963


Pagination or Media Count : 14


Abstract : An experiment designed to investigate operator variance in determining the plastic limit of cohesive soils, independent of sample preparation and hydration time, is reported. A standard sample of Grundite and pure silt was prepared, the sample was hydrated for 3 weeks, 5 random samples were taken, and 5 replicates performed on each sample. Analysis of variance showed that the sample was homogeneous at the 0.05 level of significance. Random samples were distributed to 5 zones (groups) of operators, each with different backgrounds and engineering interests. Two operators from each group performed 5 replicates. The analysis-of-variance model used in the analysis was mixed, and the upper level fixed and the 2 lower levels random. The estimated within and between operator variances were 0.45 and 4.18, respectively. (Author)


Descriptors :   (*SOILS, MECHANICAL PROPERTIES), (*SOIL MECHANICS, PLASTIC PROPERTIES), ANALYSIS OF VARIANCE, SAMPLING, MATHEMATICAL MODELS, STATISTICAL ANALYSIS, PARTICLE SIZE


Distribution Statement : APPROVED FOR PUBLIC RELEASE