Case Study: Great Lakes Water Authority (GLWA)
Watermain Condition Assessment Project – 54-Inch Prestressed Concrete Cylinder Pipe (PCCP)
Project Overview
The Great Lakes Water Authority (GLWA) partnered with KenWave, Dr. Graham Bell, and HDR to evaluate the condition of a 54-inch Prestressed Concrete Cylinder Pipe (PCCP) watermain in Farmington Hills, Michigan. KenWave’s Dynamic Response Imaging™ (DRI) technology was used to conduct a detailed condition assessment and leak detection over 0.473 miles (0.762 km) of PCCP.
The inspection was carried out over several days using temporary external sensors attached to existing access points. This non-invasive approach ensured the pipeline remained fully operational throughout the assessment, eliminating service disruptions while delivering precise, high-resolution data. KenWave’s technology provided GLWA with actionable insights to maintain and manage their critical infrastructure effectively.
Through multiple rounds of testing, KenWave’s DRI technology demonstrated its merits, identifying pipe wall properties at a resolution of 6 feet. KenWave was able to identify the areas in the pipeline that were experiencing increased degradation, these areas were indicated to the City of Gresham.
The City later excavated pipe coupons of areas with lower/higher remaining wall thickness as indicated by KenWave, in efforts to validate KenWave’s reported findings. KenWave’s DRI results were found to be within 98% accuracy of the City’s findings.
Challenges
- Large Diameter Pipe: Assessing a 54-inch PCCP requires specialized technology to deliver precise, actionable data.
- Background Noise: External environmental noise posed challenges for the vibroacoustic-based assessment.
- Traffic Control: Managing fieldwork in an active area with significant traffic required careful planning to ensure safety and efficiency.
Results
This project highlighted the effectiveness of KenWave’s DRI technology for large-diameter PCCP condition assessments. By combining high-resolution data, non-invasive techniques, and seamless integration with existing access points, KenWave provided GLWA with actionable insights to better understand and manage their infrastructure.
- High-Resolution Data: The inspection delivered residual stiffness profiles for the entire scope, providing detailed insights with a resolution of 7 feet.
- Identified Anomalies: An area of the pipe with significantly different dynamic response was detected. Upon further investigation, GLWA identified these variations as carbon fiber repairs.
