Numerical Simulation And Structural Analysis Of Ultra-diameter Prestressed Concrete Cylinder Pipe

Prestressed Concrete Cylinder Pipe(PCCP)consists of a concrete core,a thin steel cylinder,high tensile prestressing wires and a mortar coating.The concrete core is the main structural load-bearing component with the steel cylinder acting as a water barrier between concrete layers,the prestressing wires produce a uniform compressive pressure in the core that offset tensile stresses in the pipe,and the mortar coating protects the prestressing wires from physical damage and external corrosion.Based on the nonlinear analysis and damage criterion of finite element,using ABAQUS software,this paper analyzes the structure of PCCP pipeline with broken wires in Dahuofang reservoir water conveyance project,quantitatively gives the influence of the number of broken wires on the structure of the pipeline,provides reasonable suggestions for PCCP pipeline with broken wires and future safety of the project.The whole operation has important guiding significance,and it also has reference value for other large-scale water transmission and transfer projects.This paper summarized below:(1)Considered of the comparison between the current American Standard and the national standard,the crack checking calculation of PCCP mortar protective layer and pipe core concrete is carried out,and the failure mode is analyzed based on the structural calculation.(2)Based on the nonlinear finite element theory,the three-dimensional nonlinear pipe finite element model of PCCP is established.Through the simulation of the whole process of the application of loads such as prestress,earth pressure and internal water pressure,the deformation characteristics and damage trend of the pipe body are fully understood,and the failure mechanism of the pipe under the normal bearing capacity is analyzed.(3)The influence of the broken wire on the structural safety is studied from different broken wire ratio,and the influence of different broken wire areas on the simulation results of the ultimate bearing capacity of PCCP pipe with single-layer and double-layer wound wires is systematically analyzed,and then the relevant parameters of the design are optimized.