六边形输电塔体型系数与风荷载计算

摘要

六边形塔结构型式较少应用于输电塔,其体型系数仍按照四边形塔体型系数进行取值是否合理有待研究.为此,对2种不同填充率六边形角钢塔架进行了刚体测力风洞试验,研究了0°～120°风向角范围内塔架体型系数μsθ随风向角的变化规律,分析了六边形塔与四边形塔体型系数差异对塔身风荷载计算的影响.研究表明,风轴下六边形塔体型系数以60°为一个周期,体型系数最大值出现在10°和45°风向角下.在准确测定六边形塔体型系数的前提下,传统的四边形塔身风荷载计算方法仍然适用于六边形塔身风荷载计算.但在0°～15°风向角范围内,按照规范提供的体型系数计算六边形塔身风荷载偏于危险.%The hexagonal tower is rarely applied to transmission lines,and further studies are needed on the rationality of the shape coefficient of hexagonal tower represented by that of quadrilateral tower.For this purpose,two kinds of hexagonal transmission tower models with different solid ratio are established for a series of aerostatic force wind tunnel tests.Based on the test results,the change law of shape coefficient versus wind angles ranging from 0° to 120° is studied.Furthermore,the influences of shape coefficient difference between the hexagonal tower and quadrilateral tower on the calculated tower wind loads are discussed.The study shows that under the wind axis,the shape coefficient of hexagonal tower hexagonal tower presents a period of 60 degrees with the maximum value occurring at the wind angles of 10° and 45°.It is concluded that under the condition of the hexagonal tower shape coefficient being accurately measured,the traditional wind load calculation method used for quadrilateral tower is still applicable to the hexagonal transmission tower,but the calculated wind load of hexagonal transmission tower based on the code-provided shape coefficient is on the risk side with the wind angles ranging within 0～ 15°.