Abstract

All natural soils show some variation in properties due to the inherent variation in composition and consistency during formation or to the differences in testing techniques and the methods used to analyze a given set of test results. A statistical approach to the evaluation of the measured parameters offers a means to define these variabilities by providing a basis to quantify the reliability involved in the analysis. This paper presents a statistical study for the evaluation of shear strength parameters (c, Φ, ¯c, ¯Φ, Af) for Bangkok clay and makes a comparison with previous findings for this material.

The results obtained show that the variations of strength parameters can be approximated by a Beta I distribution function. The accuracy in estimating the distribution parameters depends on the number of observations. In an actual sampling there are relatively few specimens and the true mean can be estimated with some confidence limits by means of statistical analysis.

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