| Pipelines are vulnerable to damage caused by flotation as the soil liquefies during an earthquake. Centrifuge tests and numerical simulation of soil liquefaction under strong excitation were conducted in this study. A total of 10 centrifuge tests were performed using a newly manufactured laminar box. Metolose solution was used as pore fluid substitute and its effects on excess pore pressure dissipation were compared with that of water. The seismic behavior of buried pipe in metolose and water saturated soils, using laminar and rigid boxes, was investigated. A mitigation technique that used geogrid and crushed stones to resist flotation was adopted. The effectiveness of mitigation method was confirmed through the series of centrifuge testings.; A dynamic finite element procedure, based on a fully coupled stress-flow formulation, was employed to simulate numerically the centrifuge tests. Its capability for simulating liquefaction under strong and long-duration shaking was evaluated. The numerical simulation gained additional insight into the mechanism of pipeline flotation during an earthquake.; A simplified design procedure that was based on limit equilibrium was proposed for designing the buried pipe in liquefiable soils. |
