The Impact Of Prestressed Wire Spacing On Mechanical Behavior Of PCCP

Prestressed concrete cylinder pipe (PCCP) as a composite pipe, combing the advantages of steelpipe and concrete pipe, has been used in water distribution projects increasingly. In the recent years,the research on PCCP has received more and more attention. Because own structural characteristics,prestressed steel wire is very important for carrying capacity and mechanical performance of PCCP,but the impact of prestressed wire spacing on mechanical behavior of PCCP is blank, so this paperplaned to analyse it, in order to provide the basis for the industrial sector in PCCP structural design ofthe same reinforcement ratio under the wire and pitch scientific selected. And through thetwo-dimensional, three-dimensional finite element comparative analysis, this paper tried to buildthree-dimensional model from two-dimensional analytical model to simplify the method oftransformation:(1)Based on domestic and foreign research on status of PCCP finite element analysis, this paperfocuses on the difficulties existing in the modeling process of PCCP and possible solutions. Combinedwith previous research base and practical engineering problems require analysis to establish thecontent of the focus of this study; Combined with previous research and practical engineeringproblems requirement, this paper establishes the main focus of this paper-studying the impact ofprestressed steel wire pitch on PCCP mechanical performance and explores three-dimensional modelto model conversion method.(2) Based Olander distribution coefficient method, specific examples, this paper has analysed andcalculated the magnitude and distribution pattern of soil load, weight of pipe, weight of the fluid aswell as the fluid pressure.(3) Based on the loading characteristics of PCCP structure itself, this paper constructed the planestrain model suitable for PCCP force analysis. This paper conduct the stress-state analysis of PCCPunde rserviceability limited state and the carrying capacity limit state (total11kinds of workingconditions), the various parts stress-strain response of each condition of PCCP.(4)In order to study the impact of prestressed wire spacing on mechanical behavior of PCCP, thispaper has established10group PCCP dimensional model of wire pitch of0.010m,0.014m,0.017m,0.020m,0.023m,0.026m,0.029m,0.032m,0.035m,0.038m, which three-dimensional model of theaxial meshing pitch exactly coincides with the wire sapcing.Through the force analysis of the10groups model under working condition of WT3and FWT6, this paper obtained the following rules: under the action of working condition of WT3, the position of the inner core in the middle of pipe, inaddition to the individual pitch, stress value remains the same basicly, decreases with the increase ofpitch in the end position of pipe; under the action of working condition FWT6, core stress of all partsgradually decrease with the increase of spacing.(5)By two-dimensional model and the three-dimensional model of the comparative stress analysis,the two-dimensional model of the three-dimensional model is converted to the formula:M3k M2,wherein y is the three-dimensional model of the stress value calculated, x isprestressed steel wire pitch, M is two-dimensional model the stress value, k is the factor fortransforming from three-dimensional model to the two-dimensional model.