Response Simulation of Buried Pipeline During Soil Liquefaction

This paper deals with the behavior of buried ductile iron pipelines during liquefaction. Quasistatic analyses are carried out by employing a simple liquefaction model. A pipeline is modeled as a series of segmented Winkler beams connected longitudinally by joints with springs for both axial and bending motions. The modified transfer matrix method is used for numerical calculations. The results show that the probability of failure of a buried pipe due to the bending around joints is very great, since the pipeline is allowed to be floating during soil liquefaction. On the other加nd, the Probability of failure of a pipeline due to pipe bending is high in cases where the large spring constants for joint rotation are involved. Through these analyses, it becomes clear that the pipeline response is very sensitive to the evaluation of the equivalent soil spring constant. It is thus emphasized that the nature of the equivalent soil spring constant must be made clear quantitatively.