Stress Calculation Method Designed of Pipeline in Landslide Section Based on SBAS-Insar and Finite Element Method

Abstract

The permanent ground displacement of geological disasters is the main reason inducing large additional axial stress of pipelines. This paper presents a surface displacement measurement method above the pipeline based on SBAS-InSAR remote sensing technology, which realizes millimeter-level high-precision monitoring of surface displacement of pipeline in kilometer range. Based on the spatial coordinate data of the pipeline center line and the geometric feature data of the pipeline, combined with the cubic spline interpolation algorithm, a reconstruction method of the pipeline three-dimensional space routing is proposed. Considering the real routing of the pipeline and the process load conditions such as temperature and pressure, the finite element model of pipeline stress analysis is established by using the space pipe element and the nonlinear pipe soil element. Taking the remote sensing landslide displacement as the accurate boundary condition, the calculation method of pipeline stress in landslide section is proposed. The practice of a high-risk landslide section in Liangxiang-Xishatun of Shaanxi-Beijing Pipeline from 2021 to 2022 shows that the maximum relative error between the pipeline stress results obtained by this method and the distributed strain gauge monitoring results does not exceed 16%, which can effectively realize the spatial reconstruction and safety evaluation of the pipeline stress state in the landslide section, and provide a technical basis for the establishment of digital twins of pipeline safety state in future geological disaster sections.