Analysis Guidelines and Application of a Riser-Soil Interaction Model Including Trench Effects

A general overview of design aspects related to metal catenary risers is first given. Response characteristics of these types of riser configurations are considered. It is subsequently focused on models for soil-pipe interaction, which have a strong influence on computed riser stresses in the touch-down region. The so-called CARISIMA models for riser-soil interaction in relation to horizontal and vertical motion (i.e.horizontal resistance and suction) are presented. Inherent limitations of the models are summarised. Basic input parameters are described, considerations relevant for establishment of initial trench profile are given, and examples of riser response analysis are presented. Typical behaviour of the numerical models which is observed in the example analyses is also reported.