Predictability and Preventability Indices for PCCP Water Mains

Prestressed Concrete Cylinder Pipes (PCCP) are complex composite pipes which are generally used in large diameter water pipelines throughout the United States to convey large volumes of water. Therefore, prediction and prevention of failure of these pipelines is complex and requires a thorough understanding of the pipe system (structure, surrounding soil, pressure, load, etc.). This paper presents the development of a Predictability Index for PCCP as a tool to help utilities identify the pipes prone to risk and indicate the level of risk associated with each pipe. This Index is developed by understanding the various failure modes and mechanism of PCCP pipes (manufacturing, installation, operation, others). In addition, the paper also presents development of a Preventability Index providing the utilities with a guideline on the technologies and/or methodologies they could employ to identify the distress indicators their pipelines are prone to. This Index is developed by evaluating the various state- of-the-art technologies and considering the emerging technologies. The proposed Predictability (Pred) and Preventability (Prev) Indices (P&P) are evaluated and validated with the data and information collected from the Washington Suburban Sanitary Commission (WSSC), Laurel, Maryland. The proposed indices will help utilities predict and prevent PCCP pipe failures in a sophisticated manner. In the future, Predictability and Preventability Indices can be developed for other pipe materials.