Centrifuge Model Test on Performance of Thermosyphon Cooled Sandbags Supporting Warm Oil Pipeline Buried in Thawing Permafrost

Stability of the Foundation of Buried Energy Pipeline in Permafrost Region

“…In addition to full-scale experiments, some laboratory experiments are conducted to study the mechanisms for warm pipeline permafrost interactions, which are similar to the Inuvik warm pipeline experiment and the model test base on the China-Russia Crude Oil Pipeline. Since the strength and stiffness of soil are determined by effective stress, the small-scale pipeline models under gravity cannot accurately reflect the behavior of the actual pipeline, so researchers proposed centri-fuge modeling to study the pipeline's behaviors [124,126,127]. Centrifuge geotechnical tests put the smallscale model in a high-speed rotating centrifuge, allowing the model to bear the effect of centrifugal acceleration greater than the acceleration of gravity to compensate for the loss of weight caused by the reduction of the model size.…”

“…The typical model is the Canada C-CORE test; Clark and Phillips [123] operated to simulate the Calgary frost heave experiment; the results were in good agreement with the Calgary frost heave test. Li et al [124] conducted a centrifuge test of the buried pipeline in the C-CORE laboratory in Canada to confirm the effectiveness of the thermosyphon cooled sandbag mitigation applied to the China-Russia Crude Oil Pipeline (CRCOP). Many factors affect the interactions between the pipeline and permafrost, in the natural environment; the interactions are much more complicated than those in the model test.…”

“…The high temperature and ice content section of the CRCOP adopted the combination of insulation and heat pipe, replacement and heat pipe, replacement and insulation, and increased wall thickness to ensure the stability of the pipeline foundation soil. At the same time, researchers have also proposed many compound mitigation measures, such as the centrifuge test carried out by Li et al [124] that combined sandbags and heat pipes, the heat pipes cooling the soil while the sandbags supporting the pipe. The test results prove that the measure can slow the thawing rate of the pipeline foundation soil.…”