A near-wall acoustic wave-based localization method for broken wires in a large diameter PCCP using an FBG sensor array

Wire breakage induced by corrosion is the main cause of pipe bursts for prestressed cylinder concrete pipes (PCCPs). The current Rayleigh-based acoustic fiber optic methods can only locate the broken wires in 1D manner with the accuracy of pipe diameter. This paper proposed a three-dimensional localization method of broken wires in large dimeter PCCP. According to the acoustic emission characteristic of broken wires, the near-wall acoustic wave was extracted as wire-breakage sensitive feature, and the monitoring scheme based on an array of fiber Bragg grating (FBG) sensors was proposed by integrating with genetic algorithms. The feasibility of the method was verified by numerical simulations and experimental investigations. The maximum errors of the circumfer-ential angle and longitudinal distance were 2.23 degrees and 0.01 m, respectively, in the model test. The novel approach pertains to monitoring the broken wires in PCCPs at the high-risk and high-consequence zones for risk-informed operation & maintenance management.