Effects of cross-correlations between soil properties on pullout capacity of strip anchors

Plate anchors are increasingly used for floating offshore structures due to their high capacity-to-weight ratio and cost-effectiveness, but their performance is significantly influenced by spatially variable soil properties. While previous studies have considered the effects of spatial variability, the impact of cross-correlations between input soil parameters remains largely unexplored. This study investigates how the cross-correlations between soil undrained shear strength and submerged unit weight for undrained soil conditions, and between soil friction angle and submerged unit weight for drained soil conditions, influence the mean and standard deviation of anchor pullout capacity factors. Using the random finite element method a range of cross-correlation coefficients from −1 to 1 was considered. The results show that the cross-correlations have a minimal effect on the mean pullout capacity factors. However, the standard deviations increase approximately proportionally with cross-correlations, implying the importance of accurately estimating these dependencies. Assuming independence between soil parameters may lead to unconservative failure probability estimates. These findings provide insights into the role of cross-correlations in the probabilistic analysis of offshore anchors.