Study of the Effect of Cutting Frozen Soils on the Supports of Above-Ground Trunk Pipelines

Abstract

The transportation of oil and gas in Russia’s northern and Arctic regions has seen significant growth in recent years. However, the presence of permafrost in these areas can cause malfunctions in the main pipelines due to soil frost heaving. The operational pipelines also often suffer from various defects in their body and surface. To mitigate these issues, above-ground trunkline supports are utilized to protect the pipelines from cryogenic processes. Nevertheless, these supports are subjected to ground loads caused by cryogenic frost heaving, which poses a threat to the pipeline’s integrity and the environment. In response to these challenges, this study presents a design for pipeline support to maintain the pipeline’s stability in the face of soil displacement caused by unequal frost-heaving forces. A numerical model was created to evaluate the fracture of frozen rock and the resulting stresses in the soil and support structure. The input data for the model includes coefficients that describe the soil’s state during the cryogenic process and the proposed support’s parameters. The experimental results showed the proposed design to be effective in protecting the pipeline from soil frost heaving. The paper also provides the results of numerical and experimental studies on soil fracture stresses depending on the rock type and temperature. This design promises to increase both the safety of above-ground trunk pipelines and their technological efficiency.

Keywords

• above-ground trunk pipeline
• support design
• sharp edge of support slab
• permafrost soil
• frost heave forces
• soil fracture stress