Pull out Test of Offshore Platforms Mooring Lines in Very Soft Clay

Mooring lines are widely used to connect offshore platforms to anchors embedded in the seabed. The configuration of the embedded part of the mooring lines (inverse catenary) influences both the load capacity and failure mode of the anchors. On the other hand, the normal and frictional resistances mobilized during the installation of the anchors and the pre-tensioning of the mooring lines control the shape of the inverse catenary and the distribution of the load along the inverse catenary. For the success and good performance of the various analytical and numerical integration methods, as well as the numerical modeling, it is extremely important to carry out detailed laboratory and field studies to gain further knowledge on the interaction mechanisms of the chain in the soil. The present work aims to extend the theoretical approach presented in the previous paper by Sampa et al. (2020) related to this study. This work discusses the experimental results and presents different dimensionless relations that address the strain-softening behavior, displacement necessary to mobilize the maximum load and, the parameters to estimate the maximum and residual loads. These results are important to clarify many questions on soil-chain interaction in order to design offshore foundations with a high degree of confidence.