| In service submarine pipeline under high temperature and pressure often occurslateral buckling, while the restraint of foundation soil to the pipeline is the main factorto prevent this from happening. Studies show that the configuration of the buckling isdetermined by size of this restraint. So, the resistance of foundation soil to thepipeline is the most important point in the study of lateral buckling. In this paper, theprocess of how resistance works and its peak value when the pipeline does lateral andaxial movements are systematically studied through model tests, theoretical analysisand finite element simulation.Combining properties of soil in Bohai Gulf, fine sand and clay were selected todo indoor model tests to study how the resistance works when the pipeline withdifferent diameters and depths of bury do lateral and axial movements. By analyzingthe test results, regularity of the relationship between soil resistance and displacementand impacts of factors such as diameters and depths of bury etc. on peak value andfailure modes were obtained.Calculation method of peak value of soil resistance when the pipeline doeslateral and axial movement was theoretically studied and deduced as well. What'smore, based on test data, empirical formula to calculate peak value of soil resistancethat foundation soil to the pipeline suitable for sand and clay in Bohai Gulf was putforward.Finite element software was employed to simulate interaction betweenfoundation soil and pipeline, and the result was compared with test result. On thisbasis, the process how the resistance works of pipeline commonly used in Bohai Gulfwith diameter of 12 inches when it does lateral and axial movement was simulated.Also, this result was compared with the calculated peak value. And a foundation soilspring model suitable for sand and clay was established.Based on studies above, data base was provided for study on lateral buckling ofsubmarine pipeline under thermal stress.
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