Abstract
Buried pipelines are subjected to large buoyancy when surrounding soil liquefies. The pipe floats up when the buoyancy acting on it exceeds the effective overburden loads. However, it is considered that the uplift mechanismsare not only due to the equilibrium of vertical force alone, but also the shear deformation of surrounding soil induced by earthquake.
The purpose of this study is to clarify the uplift mechanism of buried pipe subjected to cyclic simple shear in dry sand.
The uplift displacement of buried pipe and contact force distributions between soil particles are calculated by the distinct element method. In addition, void ratios around the pipe are calculated to examine the behavior of surrounding particles.
It was found that the buried pipe model having a large diameter with the same density as the soil particleswas more likely to uplift compared to the soil particle that constitutes the surrounding ground. It was clarified that the buried pipe model uplifts due to the reaction force from the lower ground as the pipe model moves laterally. In addition, the intrusion of soil particles to the bottom of the pipe model was examined from the changes of void ratio of the surrounding ground.
