以某一主跨310m的独塔斜拉桥扩建工程为背景,通过节段模型测力风洞试验研究既有桥梁对其邻近新建桥梁三分力系数的气动干扰效应,引入气动干扰因子研究新建桥梁三分力系数受邻近既有桥梁影响的规律,并利用CFD手段从流场的角度定性的解释了产生干扰现象的机理。研究结果表明:既有桥梁对新建桥梁在施工和成桥运营阶段的三分力系数可能会产生十分显著的影响,并且新建桥梁三分力系数气动干扰因子随风攻角的改变在成桥和施工阶段呈现相似的规律性变化;阻力系数气动干扰因子随着风攻角绝对值的增大而增大;升力系数气动干扰因子随风攻角的增加呈递减的变化趋势,升力矩系数气动干扰因子随风攻角的变化规律较不明显。
A similar new bridge is planed to be built adjacently to an existed single-tower cable-stayed bridge which has double inclined cable planes with a main span length of 310m. Aerodynamic coefficients interference effects of the existed bridge on the adjacent new one are investigated with wind tunnel tests, the extent of interference is described with the aerodynamic interference factors, and CFD computation of wind flow is carried out at some flow cases to explore the interference mechanisms. The results show that the existed bridge could remarkably affect the aerodynamic coefficients of the new bridge. The variation patterns of the interference factors with the change of attack angles appear quite similar for both operation and construction states of the new bridge. The interference factor of the drag coefficient increases with the increase of the absolute value of attack angles while the interference factor of lift coefficient decreases with the increase of attack angles. However, it is noted that no obvious variation pattern for the interference factor of torque coefficient can be observed.