This is the first in a series of three webcasts presenting the results of Advanced Condition Assessment and Failure Prediction Technologies for Optimal Management of Critical Water Supply Pipes (project #4326).
The external corrosion of cast iron water mains can have severe implications for water utilities and has a long history of investigation. This webcast re-examined potential influencing factors by using data obtained from some 30 pipes exhumed in the Sydney and Newcastle region and a model for the development of the corrosion penetration as a function of time developed. Many of the factors traditionally thought important are shown to be of little significance, but others, seldom investigated, can have a major influence, particularly for pipes buried in clay soils and where sand surround has not been properly installed.
The second part of the webcast focused on the failure mechanisms of pipe barrel of large diameter cast iron pipes subject to traffic loads and water pressures. It presented the results of a field-scale traffic load measurement on a decommissioned cast iron pipe within Sydney Water's test bed. Water pressure and pressure transients were found to be the dominant factor in large water pipe failures. A laboratory test setup was developed for simulation of water pressure within corroded cast iron pipes and some results of pipe burst was shown to elucidate failure mechanisms. Definitions of failure were also examined, considering the key strength properties of the cast iron considering pipe cohorts.
Research partners on this project include Water Research Foundation, Sydney Water, Hunter Water Corporation, City West Water, Melbourne Water, South East Water Limited, Water Corporation of West Australia, South Australia Water, and UKWIR.