大型预应力矩形薄壁梁式渡槽静动力分析

Static and Dynamic Analysis of Large Scale Prestressed Thin-Shell-Beam Supported Rectangular-Sectioned Aqueduct

采用通用的有限元计算软件,对双洎河预应力矩形薄壁梁式渡槽进行了静动力分析。研究了渡槽在运营过程中4种计算工况下的应力、变形的变化规律。采用热-结构顺序耦合的分析方法,分析了夏季温差、冬季温差、检修和施工等工况下渡槽的温度应力分布规律。采用流固耦合理论对渡槽结构进行了动力特性分析,给出了不同水深下渡槽的自振频率和主振型。结果表明:渡槽在运营过程中,水压对渡槽的应力和变形影响巨大,风载、人行荷载和车载对渡槽的应力和变形影响较小;渡槽的局部温度应力较大;渡槽整体刚度较大,自振频率较大,水体对渡槽自振频率影响不大。

Based on universal finite element calculation software, the static-dynanfic analysis of the Shuangji River prestressed thin-shell-beam suppor- ted rectangular-sectioned aqueduct was carried out, and the change rules of aqueduct＇s stress and displacement under four cases in operational process were researched. Using the analysis method of heat and structure cnupling, we analyzed the distribution rules of aqueduct＇s thermal stress under oper- ating condition of summer temperature difference, winter temperature difference, maintenance and construction, etc. And based on fluid-solid cou- pling theory, we analyzed dynamic charaeteristics of aqueduct, providing free vibration frequency and main vibration mode of aqueduct under different water depths. The results show that, water pressure has enormous influence on aqueduct＇s stress and displacement in operational process, wind load, pedestrian load and vehicle load have less influence on aqueduct＇s stress and displacement. Local thermal stress of aqueduct is larger, overall rigidity of aqueduct is larger, so free vibration frequency is larger, water pressure has less influence on aqueduct＇s free vibration frequency.