r+k Consulting Engineers is since 1965 specialized in the strength and stability design and analysis of onland pipelines in soft soilsas they often occur in river delta areas and especially in the West of The Netherlands, where most of the areas are below sea level.
Experience with pipelines in soft soils started in 1965 with the request of Nederlandse Gasunie to design an analysis method to determine the stressing in and displacements of high pressure pipelines at dike crossings. The reason was that permits were required from the various waterboards and no method was available to prove the safety of the dike at the crossing.
Media may be hot (e.g. heavy crude oil) or cold (e.g. LNG) with low (e.g. potable water; thin walled) or high pressure (e.g. natural gas; thick walled).
Pipe material, soil properties and loadings may differ along the pipe axis. Experience is available with various pipe materials such as steels, plastics, glass fibre reinforced plastic, cast iron, concrete and even asbestos.
Various analysis methods are being applied: linear elastic and geometric structural behaviour; linear elastic and geometric non-linear behaviour; elasto-plastic material together with linear or non-linear geometric behaviour.
Analyses have been based on various Pipeline Codes: NEN 3650 (Dutch), BS8010 (Great Britain), DVGW G 463 (German), EN 1594 (European), ANSI/ASME B31.3, B31.4 and B31.8 (United States), Belgian Law.