Several design codes dictate appropriate rules for the design, construction, operation, maintenance and inspection of submarine pipelines. nevertheless, the laying operations are only briefly considered in thes codes and no methods are suggested for stress calculations during the installation process. Although many computer codes have been developed to overcome this problem, in most of the cases they do not offer a straightforward procedure suitable to be used for design purposes. In this paper, a practical procedure suitable to be used for design purposes. In this paper, a practical procedure for the computation and control of maximum stresses generated in submarine pipelines during laying operations is presented. The aim of the work is to provide a practical, simple and accurate procedure to select the most adequate laying parameters. The proposed method is based on the use of numerical correlations amont the variables involved in the physical model. Theoretical values of maximum stresses are obtained by using a Corotational Finite Element Formulation developed by the authors in a previous paper, and they are correlated to the laying parameters suing a multivariate regression technique. The laying parameters considered are the stinger length and inclination angle, pipeline diameter and thickness, buoyed length, buoyancy forces, gravity forces, suspended length and concrete coating thickness. The linear fitting model has proven to be the most convenient solution due to its simplicity and accuracy, presenting small standard errors of the stress estimates in all cases, Results are validated with real laying operations.
展开▼
