THE DETERIORATING ASSET PROBLEM
Water companies operate extensive water pipeline networks that, being developed over many years, now include significant numbers of operationally critical deteriorated pipelines. Given pipe wall deterioration contributes to major failures, assessing the influence of pipe condition on pipeline performance becomes more important over the life cycle of asset. Identifying sections with a high likelihood of failure allows selective remediation or replacement, potentially extending the life of the network.
When new, water industry pipelines are designed to meet the maximum external and internal pressure loading at specific high load locations. A newly designed pipeline is likely to have long sections operating at much higher factors of safety than necessary. However, as pipelines age and deteriorate, and when loading regimes increase, for example due to increased traffic loading, the operating factors of safety will reduce.
Recognising there can be wide ranging differences in pipe wall condition and loading along a pipelines route, our analysis is structured to allow major differences changes in the likelihood of failure to be identified. This allows remediation or replacement to be carried out only on sections of pipeline where it is required.
A range of pipe materials has been used to construct strategic pipelines. These materials have different deterioration mechanisms, failure modes and require different inspection or mechanical testing techniques to understand pipeline performance. The failure modes that occur are defined by the pipe material properties, deterioration mechanism and the applied loading regimes.