Strain analysis of buried pipelines in continuous mining subsidence areas based on shell element

Under the action of deformation, the pipeline in mining subsidence areas will produce large strain, which causes the failure of the pipeline to crack or buckling. In this paper, a 3D numerical computation model was established for study the strain of pipeline in continuous-displacement mining subsidence areas. In this model, the pipeline is simulated by the nonlinear shell element and the interaction between pipe and soil is simulated by non-linear spring element. Then, the spatial distribution characteristics of pipeline strain and its relationships with the main influential factors were analyzed on the basis of the finite element model. It is shown that when the pipeline is subjected to continuous mining subsidence, its vertical displacement is consistent with that of ground deformation, and the bending strain inside the pipeline is much smaller than the axial stain. The axial strain of the pipeline in the mining subsidence area increases with the increase of overlying strata stiffness, strike length and mining depth. The effect of the mining thickness on the axial strain is negligible. The axial strain of pipeline is increased as pipeline operating pressure, buried depth and coefficient of pipe-soil friction reduction increase, and it can be reduced effectively by increasing the wall thickness of pipeline.