Abstract:

The correlation distance is one of the important parameters for the application of random field theory to reliability analyses. The traditional methods for estimating the correlation distance are studied and improved based on the random field theory. The fluctuation function method and weighted curve fitting method are presented which can make the calculation of correlation distance easier and get a more precise result. The vertical and horizontal correlation distances of typical stratum in Tianjin Port are analyzed in statistics based on a large amount of investigation data and the representative values of correlation distance of local area are obtained. Finally, the influence of sample spacing and soil index on the correlation distances is analyzed. The principle for determining the correlation distance with the varied sample spacings is presented. In addition, it is proved that the correlation distances estimated by different soil indices are similar because the correlation distance is the basic characteristic which is used to describe the variance of soil properties.

Key words: random field, correlation distances, correlation function, sample spacing, weighted curve fitting