AWWA JAW68262

Many large-diameter cast-iron water pipelines donot have sufficient historical failure data to enablewater authorities to confidently predict failure rates.Yet when these mains fail, the costs, both direct andindirect, can be extensive. This study was undertakento develop an alternative approach for predictingfailure and scheduling replacement.The methodology presented here combines assetcondition with a physical probabilistic failure modelto determine the expected lifetime of a large-diametercast-iron pipeline. Net present-value calculations areused to determine the timing of both future inspectionsand replacement of the entire pipeline. A case studypresented in the article provides insight into how thismethodology can be applied to a drinking water distributionsystem.This modeling approach allows asset managersto maximize the usefulness of expensive inspectiondata and has the potential for improving the managementof large-diameter water mains, a challenge that iscompounded by an aging asset base and limitedbudgets. Utilities can apply these findings to help minimizethe costs and consequences of failures in large-diametercast-iron mains. Includes 25 references, table, figures.

Product Details

Edition:

Vol. 100 - No. 7

Published:

07/01/2008

Number of Pages:

10

File Size:

1 file , 580 KB