ANALYSIS OF VARIOGRAMS OF SPATIAL VARIABILITY OF THE DEFORMATION MODULUS OF HETEROGENEOUS SOIL USING CPT SENSING DATA

Nune Tigabu Abera

Estimating the variability of the soil deformation modulus (E) based on cone penetration test (CPT) data requires a multi-step process that goes beyond simply calculating the average E value for each soil layer. The modulus of deformation, a key indicator of soil stiffness and deformation characteristics, estimated by empirical correlations with CPT measurements, is depth-stratified to account for soil heterogeneity. For areas with the expected high heterogeneity, a denser grid is required. The variogram analyzes the spatial correlation structure of E values. It displays the half-dispersion as a function of the distance between the measurement points. The variograms of cone resistance (θ) qc) and sleeve friction (θ) were calculated at various depths, revealing the specific effects of nuggets and ranges indicating the correlation of these properties in different soil layers.

Keywords:Strain modulus, variograms, model fitting results, CPT data