基于实测与规范风谱的三塔悬索桥抖振性能对比  

Comparable study on buffeting performance of triple-tower suspension bridge based on measured wind spectrum and specification wind spectrum

作　　者：王浩[1] 陶天友[1] 郭彤[1] 李爱群[1] 邓稳平[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2013年第5期986-992,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51378111);江苏省交通科学研究计划资助项目(2011Y03-7);江苏省高校优势学科建设工程资助项目;东南大学优秀青年教师资助计划资助项目;同济大学桥梁结构抗风技术交通行业重点实验室开放课题资助项目(KLWRTBMC12-02)

摘　　要：为了描述三塔悬索桥抖振性能,采用实测与规范风谱进行了抖振对比研究.基于润扬、苏通桥址区多次台风现场实测数据及结构健康监测系统数据库的数据资料,采用非线性最小二乘法获得桥址区实测强风风谱模型——实测谱.以世界第一大跨度三塔悬索桥主跨1 080 m的泰州大桥为工程背景,分别采用规范谱和实测风谱为目标谱模拟了桥址区的三维脉动风场,据此开展了基于ANSYS的三塔悬索桥抖振响应对比研究.结果表明:2种主梁抖振位移PSD曲线基本一致,各方向的第一阶振型对主梁抖振响应的贡献最大;泰州大桥主梁沿跨度方向侧向抖振位移RMS分布与两塔悬索桥基本一致,竖向与扭转抖振位移RMS分布表现出了其独有特点;采用实测谱的主梁抖振响应略小,规范谱偏于保守.研究结果可用于该桥的风致抖振分析,同时可对其他同类型桥梁的抗风设计提供重要参考.In order to describe the buffeting performance of a triple-tower suspension bridge, comparative study on buffeting was conducted with measured wind spectrum and the specification wind spectrum. Based on the field measurements and database of the structural health monitoring system at Runyang Bridge and Sutong Bridge, the wind spectrum （measured spectrum） from the measured strong wind was obtained by the nonlinear least square method. As the longest-span triple-tower suspension bridge in the world, Taizhou Yangtze River Bridge with the main span of 1 080 m was taken as the example. After the 3D turbulence wind field was simulated by considering the measured spec- trum and the specification spectrum as the target spectrum respectively, comparable analyses on the buffeting response of the triple-tower suspension bridge were carried out based on ANSYS. The resuits show that these two kinds of buffeting displacement PSD （ Power Spectrum Density） curves of the main girder change with the same trend, and the first order vibration mode in each direction contributes mostly to the buffeting response. The RMS distribution of the lateral buffeting displacement along the span of the triple-tower suspension bridge is mainly the same as those of two-tower suspension bridges, while the RMS （Root Mean Square） distribution of the vertical and torsional buffeting displacement shows its own characteristics. The buffeting responses with the measured spectrum are smaller and those from the specification spectrum are therefore conservative. The results can provide references for wind-induced buffeting analysis of the bridge and wind resistant design of other bridges in the same type.

关 键 词：规范谱 实测谱 三塔悬索桥 抖振响应 时域分析 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]