Pipeline Seismic Design and Potential Mitigation Measures
Proceedings Publication Date
During the next decades hundreds of onshore or offshore oil and gas pipelines will be constructed all over the world. It is evident that the stress analysis of these pipelines is one of the most important issues of their design. However, in some areas that are characterized by moderate or high seismicity the design will be much more demanding and challenging, since many issues are directly or indirectly associated to a potential earthquake. The current paper aims to illustrate the main topics of geotechnical earthquake engineering and soil-structure interaction that have to be coped with for the proper design of pipelines. In the first part of the paper the main earthquake-related geohazards are briefly described. Seismic wave loading is the main dynamic loading for a pipeline, while quasi-static permanent deformations caused by an active-fault rupture, seismic slope instabilities, and/or soil liquefaction phenomena may be also detrimental. Emphasis is given on the second part of the paper that deals mainly with the numerical simulation of the static and dynamic interaction between the soil and the pipeline. Finally, the paper deals with the potential mitigation measures that may be adopted in the case of excessive pipeline distress. It has to be emphasized that the provisions of seismic standards, such as EC8, are not capable to cover sufficiently all the aforementioned issues. It is shown that the complexity of the specific problems requires advanced modelling and realistic simulation on a case-by-case basis. Characteristic case studies of pipelines in seismic prone areas are also presented.