SIMULATION OF PIPELINE AXIAL DISPLACEMENT IN FROZEN SOILS

Abstract

The relevance of the research is caused by the need for numerous experimental studies to determine the effect of temperature and soil moisture on its mechanical characteristics. With a change in temperature and soil moisture, the Poisson's ratio, Young's modulus, cohesion, and friction angle of the soil change. For permafrost soils, these changes are significant. They affect the stress-strain state of the underground pipeline as well as the dependence of the longitudinal displacements on the applied loads. The computer model will reduce the number of experimental research using finite element modeling. The aim of the research is to develop a mathematical model of the pipeline-soil system to study the effect of changes in the temperature of permafrost on the stress-strain state of the pipeline. Objects: underground pipelines laid in permafrost soils, subject to movements during oil and gas transportation; simultaneous influence of soil characteristics on displacement of a pipeline subjected to loads. Methods: mathematical modeling, finite element modeling in the ANSYS software package, methods of building and soil mechanics, experiment planning. Results. The authors have carried out the analysis of the pipeline soil interaction models. A 3D model of the pipeline experimental installation in a tray with a soil array was developed. The paper describes the characteristics of geomechanical theory model of the Mohr–Coulomb plasticity for the soil. The dependence of the longitudinal displacements on the applied longitudinal load in ANSYS is obtained. A comparison is made with the results obtained in the experimental installation.

Keywords

• permafrost soil
• longitudinal displacements
• monitoring
• finite element method
• stress-strain state