Pipe Burst Risk State Assessment and Classification Based on Water Hammer Analysis for Water Supply Networks

Abstract

Hydraulic transients pose many risks to urban water distribution systems. The high pressure induced by a hydraulic transient can cause pipe bursts, the negative pressure can cause pipe collapses, cavitation can cause pipeline erosions and pump impeller damages, and the transient forces can loosen pipe joints. We derived the hydraulic calculating equations based on the method of characteristics (MOC) by considering the pipe head loss and node cavitation. Four individual factors and one composite factor for hydraulic transient risk are presented along with the method of calculation of the indicators. They can produce a tabular result that is color coded by risk, and the risk classification map can be built by a four-layer state assessment and color coding technology. They are Class I with green for safe level, Class II with cyan for warning level, Class III with blue for dangerous level, and Class IV with red for severe level. The pipe burst risk assessment methods and procedures are presented. Finally, a sample model and a Chinese city pipe network system are presented for pipe burst risk classification examples.