角度风作用下输电塔塔腿子结构风荷载风洞试验

Wind Tunnel Test for Wind Loads of Transmission Tower Leg in Skew Wind

摘要:

完成了不同风速下2个典型特高压直流（UHVDC）输电塔角钢及钢管塔腿模型的高频测力天平（HFFB）风洞试验，研究了塔腿在斜风作用下气动力系数、角度风系数以及风荷载分配系数的分布规律，并与各国规范计算值进行了对比分析。分别构造了角度风系数以及考虑横向升力影响的夹角α的非线性函数形式，并通过试验值拟合分析确定了相关的拟合参数。结果表明：阻力系数、合力系数以及角度风系数均呈M型分布。角钢塔腿气动力系数均大于对应风向角下钢管塔腿的气动力系数，而两者角度风系数总体比较接近。各国规范计算值整体上低估了塔腿的角度风系数。角钢塔腿中风荷载分配系数的计算应利用考虑横向升力的夹角α对角度风系数进行三角变换。提出的拟合公式可为工程设计提供参考。

Abstract:

Wind tunnel tests with a high frequency force balance （HFFB） for the steel tubular and angle-steel tower leg models of two typical ultra-high voltage direct-current （UHVDC） transmission towers were completed at different wind velocities. The characteristics of the aerodynamic coefficients， the skewed wind load factors， and the wind load distribution factors were studied and compared with the calculation values from different standards. The nonlinear function of the skewed wind load factor and the angle α considering the transversal lift force were constructed and the fitting parameters were also determined via the fitting analysis of the experimental values， respectively. The results show that the drag coefficient， the resultant coefficient， and the skewed wind load factor are all M-shaped distribution in skew wind. The aerodynamic coefficients of the angle-steel tower leg model are always larger than those of the steel tubular tower leg model， while the skewed wind load factors of both are generally close. Compared with the calculation values from different codes， the skewed wind load factors are underestimated at almost yaw angles. In the calculation of the wind load distribution factors in the angle-steel tower leg， the skewed wind load factor should be triangulated by using the angle α rather than the yaw angle θ. The fitting formulas proposed in this paper can be used to provide references for engineering designs.