PARAMETRIC AND NON-PARAMETRIC SURVIVAL MODELS FOR "TIME TO FAILURE" OF WATER PIPELINES: CASE STUDY

An application of survival analysis on Iranian water pipelines failure dataset is employed to shed additional light on the pipeline failure process as well as to extract useful information that can be helpful in future asset management planning. Survival analysis characterizes the distribution of the survival time for different groups of pipes, to compare this survival time among different type of materials. A parametric model is developed to simulate time to failure in the pipe network. The model was calibrated on the historical failure data collected over the period 1995 - 2001, and then it was tested using data since 2002. Using both parametric and non-parametric survival models makes it possible to establish a priority list for future water pipelines rehabilitation undertakings in accordance with their material type. Accordingly, it is recommended that implementation of pipeline rehabilitation projects proceeds firstly on metallic water mains, then on plastic water mains, and finally on cement water pipelines.