Experimental Verification of Leak and Water Hammer Events in Underground Large Diameter Waterworks

Waterworks pipelines operating for a long time underground cause not only economic problems owing to leaks but also safety issues because of sinkholes. Early detection of the cause of waterworks trouble, such as leakage and water hammer, is essential for waterworks management. There are a number of studies on waterworks monitoring via vibration measurements, and fluid-coupled wave propagation, because of its long-range propagation characteristics, has gained attention in monitoring certain damages. Estimating the wave velocity along a pipeline is essential for precise localization of damages. In this study, leak and water hammer detection was performed In real large diameter buried pipelines, which are in-service waterworks pipelines with a diameter and distance of 1,100 mm and 578 m test interval, respectively. The optimal frequency band for calculating the accurate source location was determined by observing frequency characteristics. Our studies performed an empirical leak and water hammer detection in the tested pipeline, which was in a good agreement with the theoretical location analysis.