Seismic Design of Subsea Spool per ISO: Part III- Analysis & Design


Brunel University London


This is the final part of a three-part paper that presents the methodology, data needed, code check of 12-inch ID rigid pools, describing the design methodology, and key design parameters for performing the analyses. Discussion of the state of art regarding the soil data is covered in Part I. Part II is dedicated to describing ISO 19901 and 19902 seismic qualification and the derivation of design time histories. 
For each cluster end, there are two parallel flowlines each individually terminated with a Flowline Termination Assembly (FTA).  The FTA is free to move axially on its foundation to absorb movement caused by the flowline expansion and walking.  Lateral movement is restricted by lateral stops on the foundation.  Two separate spools will then be connected to a single Pigging Loop Module with a piled foundation.  A diver-less horizontal collet connector system will be used for the tie-in at both ends of the spool.
The analysis methodology which assumes the seabed is a compliant plate, is described in this paper.  For validation purposes, a couple of configurations were used to create a full three-dimensional model where the soil was modeled using the solid element with Moh-Columb behavior. These results are not presented in this paper. 


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