Towards a Classification Method for Gravity Pipeline Failures

Asset management planning for wastewater pipe networks typically uses an estimate of pipe life and scheduled replacement dates. Uncertainty in the process leads to large financial implications for local government. The use of currently collected data in decision-making is hampered by the difficulty in separating correlation from causation between pipe condition/failure, and pipe parameters (eg, material, size, construction method, soil condition). Pipeline renewal investments can arise from a wide variety of causes, some of which are unrelated to pipe age, and some of which are random events that no amount of monitoring could predict. To help further discussion, it could be useful to develop an agreed upon pipeline failure classification system.

Failures would seem to need classification based on: (1) the management path (i.e., who pays), (2) the system component that fails, (3) whether the pipe failure is because of a factor intrinsic (e.g., corrosion) or extrinsic (e.g. local settlement) to the pipe’s properties, and (4) factor(s) that contribute to the failure. The extensive experience of industry professionals would be needed to develop a classification system, and a sample is provided here to stimulate discussion.