Computer Simulation of the Stress-Strain State of a Concrete Gas Pipeline in a Swamp with Compensators Installed at its Ends

The technologies of construction and major repairs of main pipelines provide for the replacement of pipes with anchor devices and reinforced concrete weights with three-layer pipes consisting of a steel pipe, an outer continuous weighting reinforced concrete coating and an insulating layer located between them. This three-layer pipe is designated as a concrete-coated pipe in scientific and technical literature. When such pipes are used in difficult natural and climatic conditions, they float. Floating sections of the gas pipeline are classified as emergency and are taken out of operation. In this article, the problem of the stress-strain state (SSS) of a gas pipeline section in a swamp is stated and solved using the finite element method after the following changes were made to its design: pipes with reinforced concrete weights are replaced with concrete-coated pipes; G-shaped compensators are installed at the ends of the gas pipeline section in the swamp. For a section of the gas pipeline in a swamp, at the ends of which compensators have not yet been installed, the limit values of the operating parameters were found that determine the change in the shape of the pipe bend, in which the deflection arrow becomes directed upwards, and it can lead to the gas pipeline floating up. In the flooded underwater part of the gas pipeline section in a swamp with compensators installed at its ends, when the pipe bends, the deflection arrow remains directed downwards, there are no prerequisites for its floating up. The gas pipeline along the entire length of the section is stretched in the longitudinal direction, while in the flooded underwater part there is a uniform stretching of the pipe. At the ends of the calculated section, the values of the tensile-compressive stresses of the pipe in the longitudinal direction are determined from the longitudinal forces specified by the boundary conditions.