Centrifuge modeling of buried continuous pipelines subjected to reverse faulting

Abstract

Seismic ground faulting is a severe hazard for continuous buried pipelines. Over the years, researchers have attempted to understand pipeline behavior mostly via numerical models such as the finite element method. The lack of well-documented field case histories of pipeline failure due to faulting along with the costly and complex facilities needed for full-scale experimental simulation make a centrifuge-based method to determine the behavior of pipelines subject to faulting the best method to verify numerical approaches. This paper presents results from four centrifuge tests investigating the behavior of continuous buried steel pipelines that were subjected to reverse faulting. The axial and bending strains induced in a pipeline are presented. Also investigated is the influence of factors such as faulting offset, burial depth, and pipe diameter on the axial and bending strain of pipelines and on the ground soil failure and pipeline deformation pattern. Finally, the initial strain at the wrinkling point of the pipe under reverse faulting is studied and compared with theoretical values. It was found that the pipe deformation mechanism and damage type are significantly altered by variations in pipe diameter, burial depth, and pipe section slenderness ratio (diameter to thickness ratio). Increasing the diameter and burial depth of a pipe changes the deformation mechanism from beam buckling to wrinkling. The wrinkling strains from these tests are in good agreement with the findings of Hall and Newmark.