典型桁架桥梁断面静风阻力遮挡系数风洞试验

Wind Tunnel Test of Aerostatic Drag Shielding Factor of a Typical Truss Bridge Girder Section

基于典型桁架桥梁断面桁片节点测压风洞试验,研究了典型桁架桥梁断面-10°^+10°风攻角下的遮挡系数。试验结果表明:采用规范计算桁架桥梁断面成桥状态的遮挡系数,在计算间距比和实面积比时,建议将桥面铺装高度计入迎风桁架高度,将桥面铺装迎风面积计入桁架轮廓面积;遮挡系数随着风攻角的增大而减小,可以采用一次线性经验公式计算不同攻角的遮挡系数。

Based on the pressure coefficients of the truss joints from the wind tunnel test of a typical truss bridge girder section, the shielding factors from - 10° to 10° wind attack angles for a typical truss bridge girder section are researched. The test result shows that （ 1 ） when calculating the shielding factor of truss girder bridge section in completion stage using specification method, it is suggested to add the height of bridge deck pavement into the height of windward truss and to include the windward area of bridge deck pavement into the overall truss area for calculating the spacing ratio and the solidity ratio; （2） the shielding factor decreases with the increase of wind attack angle, and a linear empirical formula can be used as a possible way to calculate the shielding factors in different wind attack angles for truss girder bridge.