AN IMPROVED ANALYTICAL METHOD OF BURIED STEEL PIPELINE RESPONSE UNDER STRIKE-SLIP FAULT MOVEMENT

Considering the non-linearity of pipe-soil interaction, an improved analytical method based on axial total strain for buried steel pipelines at crossings with strike-slip faults is proposed. The bilinear stress-strain relationship of pipe steel is adopted in the method. The beam-on-elastic-foundation theory is adopted for the segments where the pipe-soil deformation is small; meanwhile, the elastic-beam theory is employed for the segments where pipe-soil deformation is large. Compared with existing analytical methods, the results of the analytical methodology presented in the paper are found in good agreement with those of 3D nonlinear finite element analysis on condition that the pipe maximum axial total stress is lower than the ultimate stress. The analytical methodology herein is suitable for engineering applications due to its exact and conservative results, as well as the greatly reduced time cost of calculation compared with 3D nonlinear finite element analysis. It is also concluded that effects of nonlinear pipe-soil interaction for large-diameter buried pipelines are of significance at smaller fault movements and crossing angles.