Soil loads on Pipelines, the Dutch approach. Proc
Kruse, H.M.G. and H.J.A.M. Hergarden (2010). Soil loads on Pipelines, the Dutch approach. Proc , 5th Pipeline Technology Conference.
The pipe stress analysis is very often the most important part of the engineering of pipelines. The different installation techniques cause different soil-pipe interaction after pipeline installation, so that in turn the soil load for the pipe stress analysis is different. In the Netherlands an approach for the determination of soil loads for the different installation methods was developed throughout the years. In case of installation of the pipe in a trench, the occurrence of settlements is an important factor for the soil load on the pipe. Besides macro settlements due to for example heightening at the surface, settlements in the trench cause an initial soil load immediately after installation, which is often normative for the engineering of the pipe. The formation of a borehole in which the pipe is installed by the horizontal directional drilling method causes a serious reduction in soil load on the pipe. Especially in granular soils the reduced soil load allows installation of plastic pipes at large depths. In compressible soils, consolidation causes a less strong reduction of the soil load. The borehole around the pipe induced by microtunnelling is caused by a slight overcut and leads to incomplete vertical deformation of the soil volume above the pipe, which leads to a less developed arching.The less developed arching yields a higher vertical soil load on the pipe, than in case of horizontal directional drilling.