预应力钢丝断丝对PCCP性能的影响

Analysis the Performance of PCCP with Broken Prestressed Steel Wires

为考察预应力钢丝断丝后PCCP性能,基于ANSYS建立PCCP有限元模型,并对有限元模型从制造、施工到断丝运行的全过程进行分析。结果表明:有限元分析结果和美国标准C304相差不大;施工过程中,对混凝土管芯而言,最易发生裂缝的区域有内层管芯内侧管顶及包角部位和外层管芯外侧管腰部位,对钢筒而言,在管芯混凝土开裂前其应力变化不大;当断丝率≤10%时,其开裂内水压力及破坏内水压力变化不大,当断丝率>10%时,在预应力等荷载综合作用下管道结构已无法继续承载。

Through the analysis of the finite element models from the stage of manufacture and construction to broken wire running which built by ANSYS,PCCP’s performance had been examined after broken wires. The results show that there’s difference between the finite-element analysis and American Standards in the manufacturing processs;in the construction process,for concrete die the inside core top and outside tube waist of in-ner core are more easily to appear cracks,the stress of cylinder has a little change. The cracking internal pressure and the destroy internal pressure have little change when the rate of broken wires are less than or equal to 10 percent. Under the action of prestressed and other loads the structure of pipe can’t be used to bear loads when the rate of broken wires is more than 10 percent.