风障对大跨度悬索桥抗风性能的影响

Effects of Wind Barrier on Wind-resistant Performance of Long-span Suspension Bridge

以主跨1 650 m中央开槽钢箱梁悬索桥为对象,进行了主梁的有风障和无风障节段模型颤振和测力风洞试验,分别对比研究了风障对颤振临界风速和气动三分力系数的影响,并利用测力试验获得的三分力系数计算分析了风障对静风稳定性的影响。结果表明:风障不会降低大跨度悬索桥的颤振稳定性;风障增大了阻力系数,减小了升力系数,在-6°—12°范围内风障使升力矩系数减小,在-12°—-7°范围内,风障使升力矩系数增大;风障不会降低大跨度悬索桥的静风稳定性,在某种程度上抑制了静风失稳,尤其是在负攻角和零攻角时。

Based on a central-slotted steel-box-girder suspension bridge with the main span of 1 650 m, the flutter performance and aerodynamic forces of a .section with and without wind barriers were tested in sectional model wind tunnel tests. The effects of the installation of wind barriers on the flutter performance and aerodynamic force coefficients were investigated with the comparison of tested results respectively. Then the effect of wind barriers on aerostatic stability was analyzed with tested aerodynamic force coefficients. The research results show that the installation of wind barriers will not affect the flutter critical wind speed of suspension bridge with this kind of girder section obviously. As for the aerodynamic force coefficients, the drag coefficient increases and lift coefficient decreases after the installation of wind barriers, while pitching moment coefficient decreases at wind attack angles - 6°-12°and increases at 12°- - 7°. The installation of wind harriers can improve the aerostatic stability to some extent, especially at negative and zero wind attack angles.