In Situ Structural Health Monitoring of Structurally Renewed Water Transmission Pipes

Cast iron (CI) pipes are a common pipe type that has been widely used over a century in many North American water transmission and distribution systems. Given their demanding operational setting, deterioration of CI pipes is now an increasingly complex management concern for utilities relying on these pipes to safely deliver water to their customers. In recent years, Class IV liners have been used to renew their structural capacity while arresting deterioration of the original pipe, thereby offering a cost-effective approach to extending pipe service lives. In this study, 107 year-old 192-foot section of a 48-in. CI water main is renewed with two different types of liners and embedded with sensors to provide continuous real-time data on the behavior and condition of the renewed pipe system for an initial period of a full year. Analyzing this data is anticipated to quantify the benefits associated with more widely adopting liners as a renewal method. Also, quantitative assessment of their long-term performance is needed to inform the optimization of future designs, verify design objectives, and identify long-term deterioration of the liner system itself. This paper describes the structural health monitoring (SHM) system that was installed in two different liner systems called steel composite liner-cement (SCL-C) and steel composite liner-polymer (SCL-P). This paper describes the design of the SHM system and highlights the performance of the SHM system to date.