Document Type : Structural Earthquake Engineering
Dept. of Civil Engineering, Kobe University
This paper investigates the behavior of polyvinyl chloride and ductile iron pipelines in relation to surface fault displacements using the Discrete Element Method (DEM) and proposes a method to estimate the allowable fault displacements. When modeling pipes and joints, the nonlinear material properties and joint characteristics (allowing detachment at the joints) are considered. Under a given set of various conditions with respect to pipe material, pipe diameter, crossing location and crossing angle, the allowable fault displacement to reach failure of the pipe is numerically simulated. The results show that a narrow angle between the fault line and the pipeline presents unsafe condition for the pipeline behavior. Furthermore, a simplified formula to estimate the allowable fault displacement is proposed, which considers joint failures due to axial forces. Estimated results achieved by this formula agree with the results obtained by numerical simulation. Finally, measures for installing pipelines with high performance joints are considered and discussed.