Estimation of Allowable Fault Displacement for Pipelines and Countermeasures

Paper addresses the behavior of polyvinyl chloride and ductile iron pipeline due to fault displacement by Discrete Element Method (DEM) and an estimation method of allowable fault displacement. In modeling of pipe and joint, nonlinear material properties and nonlinear joint characteristics (allowing detachment at joint) are considered. Under the set of various conditions with 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 narrow angle between fault line and pipeline provides unsafe condition for pipe. Furthermore, a simplified formula to estimate allowable fault displacement is proposed considering joint failures due to axial forces. Estimates from the simplified formula agree with simulation results. Finally, measures of installing pipeline with high performance joint are considered and these behaviors are discussed.