外凸式矩形高层建筑风压研究

针对外凸式矩形高层建筑结构外形复杂且其风荷载值无法通过建筑荷载规范直接获得的情况,以丝绸之路世界贸易中心外凸式矩形高层建筑为研究对象,通过风洞试验获得其风荷载值,并与规范给出的矩形结构体型系数进行对比,总结外凸式矩形建筑结构风荷载规律。基于Fluent软件,选用不同湍流模型,对外凸式矩形高层建筑进行数值模拟,并将计算结果与风洞试验结果进行比较,验证数值模拟方法的可行性。结果表明:该高层建筑迎风面的体型系数与规范接近; 背风面底部区域的体型系数比规范值大约70%,其他区域与规范值接近; 侧面体型系数均大于规范值,且最大负压出现在侧面; 对于外凸式矩形高层建筑结构,外凸结构风压较相邻区域增大,凹进结构的风压较相邻区域减小; 体型系数沿高度方向变化较大,凸出结构为迎风面时,其下方相邻区域体型系数比规范值小近50%; 数值计算结果与试验数据整体趋势基本一致; Realizable k-ε模型的数值模拟结果要优于Standard k-ε模型; 对于矩形高层建筑,凸出结构为迎风面时,其相邻上部区域和背风面下部区域风荷载不仅受凸出结构的影响,而且还受到凸出结构宽度的影响,其对体型系数的影响幅度为±20%之间。

Study on Wind Pressure of Outer Convex Rectangular High-rise Building

In view of the complex shape of the external convex rectangular high-rise building structure and the fact that its wind load value cannot be directly obtained through the building load code, the external convex rectangular high-rise building of Silk Load World Trade Center was taken as study object, and its wind load value was obtained through wind tunnel test. The wind load law of the external convex rectangular building structure was summarized through comparing the test value of the shape coefficient of rectangular structure with the value given by the code. Based on Fluent software, different turbulence models were selected to simulate the convex rectangular high-rise building, and the results were compared with the wind tunnel test results to verify the feasibility of the numerical simulation method. The results show that the shape coefficient of the windward side of the high-rise building is close to the standard. The shape coefficient of the leeward bottom area is about 70% higher than the standard value, and other areas are close to the standard value. The shape coefficient of the side is higher than the standard value, and the maximum negative pressure appears on the side. For the convex rectangular high-rise building structure, the wind pressure of the convex structure is higher than that of the adjacent area, and the wind pressure of the concave structure is lower than that of the convex structure. The shape coefficient changes greatly along the height direction. When the protruding structure is windward, the shape coefficient of the adjacent area below it is nearly 50% smaller than the standard value; the numerical calculation results are basically consistent with the overall trend of the test data; the numerical simulation results of Reliable k-ε model are better than that of Standard k-ε Model. For rectangular high-rise buildings, when the protruding structure is windward, the wind load of adjacent upper area and lower area of leeward surface is not only affected by the protruding structure, but also by the width of the protruding structure, and its influence range on the shape coefficient is ±20%.