摘要
对某大跨变截面连续钢箱梁桥跨中断面、1/4跨断面、支点断面进行了节段模型风洞测力试验,并对主梁进行了二维和三维数值模拟,通过风洞试验结合数值的方式来研究连续钢箱梁桥变截面主梁展向、腹板高度变化及梁底线形不同对于模型静三分力的影响。结果表明,腹板高度变化及梁底线形不同对连续钢箱梁桥静气动力系数有显著影响,随腹板高度增大,变截面连续钢箱梁桥阻力系数、升力系数、扭矩系数均有显著增加;在梁底线形为直线且斜率较小时,模型的静三分力不会随梁底直线斜率的变化而产生明显的变化,在风洞试验及数值模拟中可以用等截面的节段模型来代替梁底有斜率的节段模型。而当梁底直线与水平线夹角大于3°或梁底线形为二次抛物线时,计算得到的静三分力系数与等截面模型的结果相对变化量较大,故对于变截面梁在这种情况下不宜使用等截面的节段模型进行风洞试验,且应尽量采用三维流场数值模拟与实桥梁底线形相一致以提高计算精度。
The segment model wind tunnel test out on the mid-span section, 1/4 span section and support section of a long-span continuous steel box girder bridge with variable sections is carried, and the 2 D and 3 D numerical simulations are performed on the girder. The influence of the girder span direction, change of web height, and line shape of the girder bottom of the subject bridge on the static three-component force of the model is examined by wind tunnel experiment and numerical simulation. The result shows that(1) the variation of web height and the line shape of the girder bottom can significantly affect the static aerodynamic dynamics coefficient of the continuous steel box girder bridge, the resistance coefficient, lift coefficient and torque coefficient of the subject bridge significantly increase as the web height increase;(2)when the line shape of the girder bottom is straight with a small slope, the static three-component force of the model would not obviously change with the straight line slope of the girder bottom, and the segment model with equal section can be used to replace the segment model with slope at the bottom of the beam in wind tunnel experiment and numerical simulation;(3)but when the angle between the straight line of the girder bottom and the horizontal line is greater than 3° or the line shape of the girder bottom is a quadratic parabola, the calculated static three-component coefficient has a big relative variation compared with the result obtained from the equal-section model. Therefore, it is not suitable to use the segment model of equal section for wind tunnel experiment for the variable section girder bottom in this case, and it is recommended to use 3 D flow field numerical simulation that is consistent with the line shape of the actual bridge bottom as far as possible to improve the accuracy.
作者
李加武
宋特
林立华
姬乃川
霍五星
LI Jia-wu;SONG Te;LIN Li-hua;JI Nai-chuan;HUO Wu-xing(School of Highway,Chang'an University,Xi'an Shaanxi 710000,China;Xiamen Road and Bridge Engineering Investment Development Co.,Ltd.,Xiamen Fujian 361000,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2020年第4期88-95,共8页
Journal of Highway and Transportation Research and Development
关键词
桥梁工程
静三分力系数
数值模拟
变截面
连续钢箱梁桥
bridge engineering
static three-component force coefficient
numerical simulation
variable cross-section
continuous steel box girder bridge
