Pullout Test Study on Flexible Joint of Ductile Iron Buried Pipelines

Axial pullout test on ductile iron buried pipelines with MTS testing machine was carried out, the relation curve between axial tension and flexiable joint displacement was gotten, the functional failure mechanism of flexible joint of buried pipeline was discussed. The results indicate that there is relative displacement between pipe and soil under seismic action, meanwhile, the acting force between pipe and soil is the viscous damping force which is related to pipe-soil relative speed.