ABSTRACT
Risk assessment in geotechnical engineering requires consideration of uncertainties and variabilities in soil parameters. These uncertainties result from measurement errors, transformation uncertainties and inherent soil variability. In this study, the variability of soil properties in Turkish offshore sea beds are investigated based on nine CPT measurements in 40–64 m water depths. Statistical evaluation of the CPT tip resistance and sleeve friction data is performed and vertical spatial correlation lengths are reported for clays and sands, separately. The effects of the spatial correlation length and coefficient of variation on the probability of failure and bearing capacity of a shallow strip foundation on c ϕ soil (with cross-correlation between shear strength parameters) are investigated. The bearing capacity analyses are performed by two-dimensional random finite element method using plane strain condition and Von Mises constitutive model for the soil. Shear strength parameters, stiffness and dilation angle are assumed to be lognormally distributed random variables. The results of this study indicate that the variability of soil parameters, in terms of coefficient of variation and vertical spatial correlation length, has a significant effect on the bearing capacity and probability of failure.
