Serviceability assessment of prestressed concrete cylinder pipes with broken wires: Analytical solution and numerical simulation

Wire breakage is the most prevalent type of damage to prestressed concrete cylinder pipes (PCCPs) as widely used in large-scale water supply projects. Based on the elastic mechanics theory, the distribution of deflection, bending moment, shear force, and strain along the length of PCCP after wire breakage is calculated in this work. A three-dimensional finite element (FE) model of PCCP is also established. The analytical and numerical models for PCCP with intact wires are then evaluated using a full-scale test. Furthermore, the two analyses on PCCPs with broken wires are compared and assessed against each other. Upon calibration, the impact of broken wire width on the responses of PCCPs is investigated. Finally, the wire breakage thresholds of PCCPs with different inside diameters and steel wire areas are determined. The findings reveal that wire breakage has a limited influence on the pipe's force distribution, showing little changes in the force state within 1/3 of the pipe's length at both ends. The broken wire threshold increases with the steel wire area for pipes with an inside diameter of 1400 mm, although the increasing trend slows down. Under the action of internal working pressure, different pipes reach their serviceable limit states once their wire breakage ratios are beyond a certain value, (i.e., 7.4%, 7.7%, 8.3%, 10.4%, and 14.1% for PCCPs with a steel wire area of 787, 910, 1088, 1317, and 1598 mm(2)/m, respectively).

Automated summary

This study investigates the effects of wire breakage on PCCP and determines the wire breakage thresholds for different conditions. The results show that wire breakage has a limited impact on the force distribution of the pipe, but the threshold increases with the steel wire area.