基于风洞试验的苏通大跨越输电塔风振系数研究

苏通大跨越输电塔的结构形式有别于普通的钢结构杆塔，其塔身下部结构采用钢管混凝土、上部结构采用钢管，质量突变大，主要受风荷载控制，并且塔高超出GB 50009—2012《建筑结构荷载规范》的梯度风高度限制。为此，采用气动弹性模型和刚性模型的边界层风洞试验确定苏通大跨越输电塔的风致响应和气动力，基于试验数据计算不同风向角下的惯性力风振系数、位移风振系数和有效荷载风振系数，并进行对比。并通过有限元分析梯度风高度对惯性力风振系数的影响，同时将有限元分析得到的风振系数分布和加权值与DL/T 5154的风振系数规定作比较。结果表明：上述3种风振系数分布规律并不相同，由其分别确定的等效位移接近于试验值；考虑梯度风高度后，风振系数变小，分布形状影响小；苏通大跨越输电塔的惯性力风振系数加权值小于1.6，且风振系数由下到上不是单调增大。

Investigation on wind-induced vibration coefficients of Sutong long span transmission tower based on wind tunnel tests

The structure form of Sutong long span transmission tower is different from that of ordinary steel towers. Because tower substructures consist of concrete-filled steel tube and tower superstructures consist of steel tube, the mass mutation of tower is significant, thus the tower is mainly affected by wind load. Besides, the height of the tower exceeds the limit of gradient wind height in code GB 50009—2012. Therefore, wind-induced responses and aerodynamic forces of Sutong long span transmission tower were acquired by the boundary layer wind tunnel test of an aeroelastic model and a rigid model. Based on these test data, the inertial force wind-induced vibration coefficient, displacement wind-induced vibration coefficient and effective load wind-induced vibration coefficient were calculated under different yaw angles, and these coefficients were compared with each other. Moreover, the influence of gradient wind height on the inertial force wind-induced vibration coefficient was analyzed through finite element analysis. Further, the distribution and the weighted value of wind-induced vibration coefficient acquired by finite element analysis was compared with the regulation of DL/T 5154. The results show that the distributions of the three types of wind-induced vibration coefficients are different, and the equivalent displacements determined by them are close to the test values; after the gradient wind height is considered, the wind-induced vibration coefficient decreases, but the change of its distribution shape is small; the weighted value of the inertial force wind-induced vibration coefficient of Sutong long span transmission tower is less than 1.6, and the wind-induced vibration coefficient is not monotonically increasing from the bottom to the top.