Structural Safety Assessment on Super Caliber Prestressed Concrete Cylinder Pipes

摘要

Prestressed concrete cylinder pipe (PCCP) tends to be of large diameter,making many failures of this pipe relatively catastrophic and costly.To date,most researches have been focused on PCCP inspection technologies and performance prediction in order to minimize the risk of accident.The performance of Prestressed Concrete Cylinder Pipe has been an interesting item of water utilities for a long time.Judged from the research progress at home and abroad,researches on numerical calculation of PCCP are lack of experimental verification.Furthermore,there are not any achievements in experimental research on super caliber PCCP (diameter＞4m).In the paper,by the prestress relaxation,broken wires and the bearing performance tests of prototype large-caliber PCCP,the bearing characteristics and damage mechanism of PCCP were analyzed by the inner pressure and three-point external load tests.Aiming at the anti-crack external pressure experiment of PCCP,the effect of stored vertical cracks at the outer surface was discussed.The structure performance of PCCP was analyzed by applying the damaged plasticity model of concrete.The numerical calculation results were consistent with the experiment results.The numerical results show that the anti-crack external ultimate load had little effect by the core concrete crack.But the stress of concrete and mortar was concentrated around the crack and the damage of concrete appeared under the load.The whole work made up gaps for prototype PCCP test with the source of innovation and practical theoretical significance.