Uplift Response of Large-Diameter Buried Pipeline in Liquefiable Soil Using Pipe-Soil Coupling Model

Abstract

Buried pipelines are vulnerable to damage caused by flotation as the soil liquefies during an earthquake. In this paper, in order to analyze the cross-sectional deformation of large-diameter and thin-wall (φ1016×21mm) buried pipeline under liquefaction-induced uplift force, a comprehensive three-dimensional pipe-soil coupling model, based on pipe-soil Interaction and thin shell theory, is developed. Utilizing the model, uplift response of buried pipeline under different conditions are simulated and the effects of several important parameters including width of liquefied zone, ratio of diameter to thickness (D/t), burial depth, and strength of soil spring are studied. The results show that the maximum ovality ration and strain of pipeline under liquefaction-induced uplift force increases with increasing width of liquefied zone, soil spring strength, burial depth and ration of diameter to thickness. Width of liquefied zone and soil spring strength are critical parameters, which have large effect on deformation of buried pipeline, however, the ratio of diameter to thickness and burial depth of pipeline affect the uplift response of pipeline slightly. According to the results obtained, some useful suggestions for the design of large-diameter buried pipelines in liquefiable soil are given.