Interaktion zwischen Fernwärmeleitungen und dem umgebenden Boden

Interaction of district heating pipelines and the surrounding soil

District heating pipelines are subjected to significant temperature changes and therefore interact intensively with the surrounding soil, which hinders the temperature-induced deformation of the pipeline. The axial deflection mobilizes friction forces and the lateral deflection occurring for instance in arc sections mobilizes bedding resistances. Both soil resistances change with operation period of the pipelines due to cyclic load effects. Moreover, the maximum friction force depends on the operation temperature of the pipeline. The bearing behavior of the pipeline is thus quite complex. In the current design guidelines the complex behavior is considered only in a very simplified way. The report at hand summarizes the knowledge concerning friction forces and bedding resistances and describes an approach followed in a current research project to consider the bearing behavior of earth-buried district heating pipelines more accurately.