Calculation model for strain of buried pipeline under the action of continuous surface displacement

The long-distance oil & gas pipelines run through areas with various complicated geological conditions and often face the threats of geological hazards. In terms of the discrete characteristics of the surface displacement monitoring data in existing pipeline sections threated by geological disaster, a three-dimensional reconstruction method of surface displacement based on cubic spline interpolation (CSI) was proposed to realize the continuous representation of surface displacement. Then, the pipe-soil interaction was described using the nonlinear soil spring element with the nonlinear finite element method, the pipes were described with the Ramberg-Osgood constitutive model, and the parametric calculation model for strain of buried pipeline under the action of continuous surface displacement was established with the INP parametric programming language. The new model takes the influence of the working load (such as temperature and pressure) and the actual route of the pipeline on the initial stress of the pipeline into consideration, and realizes the accurate calculation of the pipeline strain. The intelligent calculation and evaluation software for the design strain of pipelines based on the C/S architecture was developed with the C# programming language. The research results provide technical support for the Digital Twin construction of intelligent pipelines and the integrity evaluation of pipelines in geological hazard area.