刚性桥面板天然气管道悬索跨越结构力学性能

Research on Mechanical Property of Cable-Suspended Structure of Liquefied Natural Gas Pipelines with Rigid Deck Slab

建立刚性桥面板天然气管道悬索跨越工程原型的有限元计算模型,并对有限元计算模型进行静力、模态和清管反应的有限元分析.结果表明:在成桥状态下,与设计资料对比,悬索跨越结构的整体位移曲线满足设计精度要求;天然气管道悬索跨越结构的前3阶模态均为平面内桥身的振动,直到第4阶才出现主缆的振动,在第6阶出现桥面板的平面外振动;清管球通过跨越结构时间为110,120s的跨中竖向位移-清管球位置曲线发展完整,两个波峰和一个波谷并且整个的曲线形状同静力分析的形状大致相同;随着清管球经过全桥的时间不断减小,曲线发展得越来越不完整,第一个波谷出现的位置也不断地向坐标轴的右边推移,第二个波峰没有出现,其中通过时间为30,40s的曲线甚至没有出现第一个波谷.

The finite element model of engineering prototype of cable-suspended structure of liquefied natural gas pipe-lines with rigid deck slab is established,and the static,modal and pigging response are carried out.The whole displace-ment curve of cable-suspended structure under dead load,meets the design accuracy by comparison with the design data;The first three rank modes of cable-suspended structure of liquefied natural gas pipelines are in-plane vibration of bridge, the vibration of main cables appears at the fourth rank,the out-plane vibration of bridge deck appears at the sixth rank. Mid-span vertical displacement-position of pigging ball curve of pigging ball taking 120 s and 110 s to cross suspended structure develops completely,appearing two wave crests and one trough,and the shape of whole curve is similar to the shape of static analysis.With the time of pigging ball through bridge decreases,the development of curve is more and more incomplete,the position of the first trough moves continuously to the right of axis,the second wave crest does not appear,when the crossing bridge′s time is 30 s or 40 s,the curve of even does not appear the first trough.