effect of sampling interval on the scale of fluctuation of cpt profiles representing random fields

One of the most important statistical parameters in modeling the spatial correlation of soil properties in a random field is the scale of fluctuation (sof), which is strongly affected by the sampling interval. in this study, the effect of the sampling interval on the sof in the vertical direction was examined using cone tip resistance (qc) profiles of 70 cpt datasets. the qc data intervals in the vertical directions were 2.5 cm, 5 cm, 10 cm, 20 cm, 40 cm, 80 cm, 160 cm and 320 cm. the direct integration of sample autocorrelation function method with quadratic trend removal was adopted to determine the sof. variation of the calculated sof versus the extended sampling intervals demonstrates that the sof increases with the increase in the sampling intervals. results show that the determined sof values based on the geotechnical data sampling intervals up to 40 cm are presumably more reliable. limiting the sampling interval will contribute to the preservation of important correlation information of geotechnical site investigation data.