Analysis of the General Stability of Buried Pipelines in the Longitudinal Direction Taking into Account the Peculiarities of Their Construction and Operation

Abstract

Abstract Main oil and gas pipelines should be checked for overall longitudinal stability. In this case, the longitudinal compressive force in the cross-section of the pipeline, leading to the loss of its stability, is determined by the effect of a positive temperature difference in the metal of the pipes and the working pressure in its cavity. The longitudinal critical force, at which the loss of longitudinal stability of the pipeline occurs, is determined according to the rules of structural mechanics in the plane of the least bending stiffness of the system taking into account the constructive solution of its laying. The value of the longitudinal critical force of a buried pipeline depends on the geometric characteristics of the pipe, its weight with the pumped product, the parameters of curvature of the longitudinal axis of the pipeline when it is laid along the terrain, and the resistance of the soil to its longitudinal and transverse displacement. During operation, due to a decrease in the resistance of the soil surrounding the pipeline to its movements for various reasons, a decrease in the critical force occurs. Loss of stability of a buried pipeline occurs in the plane with the least bending stiffness of the system. With the help of theoretical studies of the general stability of buried pipelines, analytical dependences of the longitudinal critical force for a buried pipeline were obtained on the basis of taking into account the curvature of the longitudinal axis of the pipeline during construction and reducing the resistance to displacement of the pipeline during its operation for 5 different design schemes.