BUCKLING ANALYSIS OF BURIED PIPELINE SUBJECT TO REVERSE FAULT CROSSINGS

Local buckling or overall buckling failure of large-diameter buried pipelines through reverse fault is prone to take place under ground permanent deformation induced by earthquake fault, which makes the pipelines damaged and even out of work. In this paper, the stability (buckling) of buried pipeline under reverse fault crossings was studied. An integral mechanical model was established with buried pipeline and the surrounding soil being considered together, and the pipeline was simulated as thin-shell element, while the surrounding soil was modeled as solid element. The linear eigenvalue-buckling analysis method and the Riks method considering nonlinear influence were adopted to study the overall and local buckling of the buried pipelines subjected to reverse fault. The critical load (forced fault dislocation) and buckling modes corresponding to different eigenvalues were given according to example analysis. It was found that the eigenvalue buckling analysis method was feasible to forecast critical buckling load. Based on the analysis of steel-pipe and PE-pipe, the buckling responses of the pipelines and variety trends were investigated with different pipe-diameter, wall-thickness, fault crossing angle, soil shear velocity, buried depth and angle between pipe and fault .