Plastic Design of Buried Steel Pipelines for Transport of Oil, Gas or Water, Verified by Tests on Scale Models

摘要

In the Netherlands an extensive system of pipelines has been constructed in the last 10-15 years. Difficulties have been encountered at points where the pipelines have to cross existing dykes. Because of the often highly compressible subsoil (peat and clay strata), differential settlement is liable to occur after the construction of such crossings. As a result, the pipeline is subjected to imposed deformations. The pipeline must be able to adapt itself to these differences in settlement. That means that not only the strength is important, but especially the deformation capacity. Until yet the methods of design and analysis of steel pipelines are based solely on the elastic theory (in the Netherlands anyway). This elastic theory provides a very incomplete picture of the essential deformation capacity. Research has shown that the behavior of buried steel pipelines under imposed deformations can be described much better with the aid of the plastic theory. Some important results which have emerged from that research are presented in this report, which is concerned with model tests and with a theoretical treatment of the subject. The background and the main features of proposed new design recommendations are also dealt with.