LAUSR

Abstract Damage-induced breaking of prestressed steel wires is one of the major causes of failure of prestressed concrete cylinder pipes (PCCPs). In this study, an internal pressure test of a full-scale PCCP model was conducted to measure the strain response of different layer structures of PCCP under internal working pressures with a broken wire percentage of 0% (intact), 5%, and 10% and to obtain the load response of the pipe with broken wires during the pressurization process. The test results showed that after the breaking of the prestressed wires, the prestress field was redistributed, caus ing cracks to first appear in the broken wire area. The strain of the concrete core in the broken wire area increased suddenly at the instant of wire breaking, generating circumferential microcracks, and the strain of unbroken wires on the side of the wire cut-off position increased as the number of broken wires increased. As the degree of wire breaking was increased, the degree of cracking at the broken wire section of the pipe significantly increased. When the percentage of broken wires reached 10%, longitudinal cracks occurred in the core concrete of the broken wire area, forming a weak zone in the pipe. A three-dimensional numerical model of a PCCP with broken wires was established based on the actual structural parameters of the test pipe and accounting for the bond stress of the protective mortar coating. The load-carrying capacities of PCCPs with broken wire percentages of 5%, 10%, 15%, 20%, and 25% were analyzed. Simulated and experimental results were compared, showing good agreement.