角钢输电塔杆件风压及体型系数的风洞试验研究

Wind tunnel tests for wind load distribution and shape coefficient of angle-made-transmission towers

以220kV角钢输电塔为研究对象,设计制作了1∶2.5的大比例刚性节段模型,在均匀湍流场中进行同步测压风洞试验,获得了输电塔主材、斜材和辅材杆件的风压分布规律和体型系数沿杆件展长的分布.归纳了风荷载对塔身各杆件的作用特点以及体型系数随风向角的变化规律.对于角钢杆件,当角钢内角迎风时,阻力系数与升力系数均较大,杆件处于双向受力状态.对整塔段的体型系数进行了试验值和国内外规范取值的对比.结果表明:按我国规范取值偏小,试验值与国外规范取值接近.

An angle-made transmission tower with 220 kV was researched. A 1 ： 2.5 large scale rigid section model was fabricated and the wind tunnel measuring pressure test was performed in homogene ous turbulence flow. The wind pressure distribution and shape coefficient along main members, ob- lique members and auxiliary members were obtained. The characteristic of wind load functioning on each member was induced, and the law of varying shape coefficient of each member＇s sections along with wind angle was summarized. It shows part of the angle steels which have both large drag and lift coefficients are under the action of double-direction distributed wind load in some specific wind direc- tions. The standard value was compared with the tested value of the section model＇s shape coefficient. The result shows that the domestic standard value is smaller than the tested value which tends to be unsafe to structure design, while the foreign standard value well agrees with the tested value.