Soil resistance acting on buried pipelines in Bohai Bay soft clay

During the design of submarine pipelines, it is a crucial problem to determine the interaction between the pipeline and the subsoil. The uplift, lateral and axial soil resistances acting on the pipelines are investigated considering the moving directions of the pipelines in the thermal overall buckling analysis. Soft clay is chosen as the supporting medium in view of geotechnical conditions in Bohai Gulf. A series of model tests are carried out to facilitate the establishment of substantial data base for a variety of burial pipeline topologies. In the tests, the pipes with different diameters are buried with different depth-to-diameter ratios. The uplift, lateral and axial resistances are recorded during the tests. Based on the test data, a numerical method is established and used to analyze an actual dimensional pipeline in practice. The test results show that the uplift and lateral soil resistances depend on the pipe diameters and cover depth more greatly than the axial soil resistance. According to the test data and numerical results, the experimental formulae are proposed to determine the maximum soil resistance and the corresponding displacement of pipelines for all their three moving directions.