Research Progress on Monitoring and Reinforcement of Prestressed Concrete Cylinder Pipe

Prestressed Concrete Cylinder Pipe (PCCP), as a composite pipe material with high strength and good durability, is widely used in urban long-distance water transmission projects in China. Its main structure includes the steel cylinder, concrete, prestressed steel wires, and a mortar protective layer. However, over the long-term use of PCCP, problems such as cracks in the cement mortar protective layer, longitudinal cracks in the concrete wall, corrosion of circumferential prestressed steel wires, and wire breakage gradually emerge, leading to the degradation of pipe performance and even rupture accidents. Therefore, the safe operation of PCCP during its service life has attracted widespread attention from researchers. This paper provides a detailed review of the wire breakage monitoring technologies and reinforcement methods for PCCP, focusing on the wire breakage monitoring methods based on electromagnetic principles and distributed optical fiber sensing technology, and their applications in PCCP. In addition, this paper also introduces CFRP reinforcement technology and external prestressed reinforcement methods for PCCP pipe wire breakage issues. External prestressing has particular advantages over CFRP, which is commonly used for internal reinforcement, for in-service long-distance pipelines. Research shows that the use of modern non-destructive testing technologies and reinforcement methods can significantly enhance the safety and service life of PCCP pipes, especially in emergency repairs.