A Simplified Limit-State Design and Verification for Prestressed Concrete Cylinder Pipes under Internal Water Pressure

Abstract

Ignoring the effect of a concrete core on bearing performance, the current design of prestressed concrete cylinder pipes (PCCPs) under internal water pressure only focuses on the fracture of prestressed steel wire, while the complexity of the AWWA C304 design method leads to a strong dependence on software that cannot be sufficiently mastered by the designers. In view of these issues, a simplified limit-state design process was induced to eliminate a large number of iterative operations and was verified by a three-dimensional finite element model (FEM) with a prototype test of PCCPs under internal water pressure. Meanwhile, the bearing performance of PCCPs was investigated using the parametric simulations of the FEM. The results showed that the cross-sectional area of the prestressed steel wire is higher by about 10% than that designed using the AWWA C304 method. The FEM provides a complete evolution process of the mechanical response of the structural constituents and simulates the strain mutation phenomenon of the prototype test well. The internal water pressure of the PCCPs designed using the simplified limit-state design process has enough safety to reach 4.7 times the working pressure at serviceability and 5.5 times the pressure at the ultimate limit state. A burst in the PCCPs took place under an internal pressure greater than 6.75 times the working pressure. The result of the FEM shows that an increase in the tensile strength of the concrete core is of great significance for improving the bearing performance of the PCCPs.

Keywords

• prestressed concrete cylinder pipes
• simplified limit-state design process
• finite element model
• concrete strength
• bearing performance