Abstract
This paper proposes a new practical method to evaluate soil parameters for performance based design. The characteristic value of soil parameter is the expected value in principle, but it is not the mere average. We should take into account of errors statistically estimated, errors in derived values associated with testing methods, inhomogeneity of the soil itself, and limited number of test data. The new method uses a correction factor based on the variation coefficient derived from the soil data. In this method, the characteristic value automatically reflects the variability of derived values associated with the testing method and the reliability of the data interpretation.
