超大跨组合梁斜拉桥静力非线性影响研究  

Research on Static Nonlinear Effects of Super Long Span Composite Beam Cable-stayed Bridges

作　　者：汤虎 TANG Hu

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《上海公路》2023年第4期32-38,46,I0009,共9页Shanghai Highways

基　　金：上海市青年科技启明星计划(21QB1404700)。

摘　　要：以主跨1 000 m组合桥面板组合梁斜拉桥试设计方案为背景,采用数值模拟手段,研究了不同的非线性效应对超大跨组合梁斜拉桥动静力性能的影响。采用修正拉索弹模、多段杆单元等手段来模拟拉索垂度效应,与是否考虑梁柱效应及大位移效应相组合,共计算了六种非线性计算分析工况。研究结果表明,对千米级组合桥面板组合梁斜拉桥,斜拉索垂度效应引起的活载非线性效应并不十分显著,引起的结构内力及位移非线性效应误差总体上在5%以内。三种几何非线性影响因素中,梁柱效应最大,大位移效应次之,而拉索垂度效应最小。考虑到几何非线性对结构动力特性有一定影响,总体上,结构振动频率减小,但对斜拉桥颤振临界风速直接相关的一阶扭转频率影响不大,影响幅度不超过2%。Taking the trial design scheme of a 1000 m main span cable-stayed bridge with composite bridge deck as the background,the influence of different nonlinear effects on the dynamic and static performance of a super long span composite beam cable-stayed bridge was studied by numerical simulation.Six nonlinear calculation and analysis conditions were calculated by using methods such as modified cable elastic modulus and multi segment rod elements to simulate the cable sag effect,while considering the beam column effect and large displacement effect.The research results indicate that for 1 000 m-level composite bridge deck composite beam cable-stayed bridges,the nonlinear effect of live load caused by the sag effect of the stay cable is not very significant,and the error in the nonlinear effect of structural internal force and displacement caused by this effect;is generally within 5%;Among the three geometric nonlinear influencing factors,the beam column effect is the largest,followed by the large displacement effect,and the cable sag effect is the smallest.Considering the influence of geometric nonlinearity on the dynamic characteristics of the structure,the vibration frequency of the structure decreases,but the first-order torsional frequency directly related to the flutter critical wind speed of the cable-stayed bridge has litle effect,with an amplitude of no more than 2%.

关 键 词：斜拉桥 组合梁 拉索垂度效应 梁柱效应 大位移效应 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]