大跨度公铁两用斜拉桥三维风速场实测与模拟  

3D wind field measurement and simulation of a long-span cable-stayed rail-cum-road bridge

作　　者：徐曼[1] 郭薇薇[1] 夏禾[1] 张楠[1] XU Man;GUO Weiwei;XIA He;ZHANG Nan(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《哈尔滨工业大学学报》2019年第3期107-113,共7页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金(51878036;51720105005;51508018;U1434205)

摘　　要：为得到沪通公铁两用长江大桥(后简称沪通大桥)桥址区风速时程序列,对沪通大桥开展了现场风速实测,对桥址区的风场特性进行分析,得到基于实测数据的风速谱,并将其与规范给出的风速谱进行参数对比.之后采用基于实测风速谱显式分解的谐波合成法,将该桥的三维脉动风速场简化为多个线状的一维脉动风速场,分别对两个主塔、公路桥面、铁路桥面的脉动风速进行数值模拟,模拟值与目标值吻合较好.结果表明:采用实测的风速谱参数可以很好地得到大跨度桥梁数值模拟三维脉动风场,并与规范给出的统一功率谱有一定的差异性,体现了规范谱应用于不同地区,尤其是复杂气象条件时的局限性.得到的基于实测风特性的大跨度斜拉桥风速时程序列,为桥梁的风振分析提供了基础,具有良好的实用效果.In order to obtain the wind velocity histories of Hutong rail-cum-road Yangtze River Bridge, an in-situ wind field test of the cable-stayed bridge was carried out. The wind field characteristics were analyzed, and the wind velocity spectra parameters of the experiment were compared with those of the specification. By means of harmonic synthesis method, this paper simplified the 3D turbulence wind field into multi 1D turbulence wind filed, and simulated the turbulence wind velocity histories of two towers, the girders on roadway and on railway deck separately. Results showed that the 3D turbulence wind velocities obtained based on in-situ test records fitted well with the target value, and exhibited differences with the specification values. It indicates that the application of specification spectra values is limited when used in different regions, especially in regions with complex climate conditions. The wind velocity histories of the long-span cable-stayed bridge obtained can be used in bridge aerodynamic analysis, which is pragmatic for engineering purposes.

关 键 词：斜拉桥 风场实测 脉动风功率谱 数值模拟 谐波合成法 

分 类 号：U448.43[建筑科学—桥梁与隧道工程]