高层建筑水平悬挑遮阳板风荷载的风洞试验研究

高层建筑悬挑遮阳板等小尺寸构件直接承受风荷载作用，在强风作用下的安全性备受关注。相对于建筑的整体尺寸，悬挑遮阳板很小，难以在缩尺模型上直接模拟，因此在实际工程的风洞试验研究中常常被简化或者忽略。研究中利用3D打印技术制作了精细化的有悬挑遮阳板的高层建筑风洞试验模型，并在打印遮阳板模型时直接预留测压管道，分析了水平悬挑遮阳板的风压分布规律及遮阳板对建筑立面风压的影响，并对基于建筑立面风压的悬挑遮阳板风压估计方法的估算误差进行了评估。研究结果表明：高层建筑水平悬挑遮阳板的最不利净风压的最大值出现在顶层遮阳板处；水平悬挑遮阳板的存在能较大程度地削弱建筑立面上的最不利负风压；悬挑遮阳板最不利风压可利用其上下两侧附近建筑立面测点的风压差近似估计，但对于建筑立面边缘附近的悬挑遮阳板端部以及建筑底部附近的最底层悬挑遮阳板上的最不利风压，这种方法的估算误差较大。

Wind tunnel test study on wind load of overhanging horizontal sunshade of high-rise buildings

Small size members of high-rise building such as overhanging sunshades bear wind load directly, whose safety under strong wind have attracted much attention. Compared with the overall size of building, their tiny size makes it difficult to be simulated on scaled model, so they are often simplified or ignored in wind tunnel tests of practical engineering. In this study, a refined wind tunnel test model of high-rise building with overhanging horizontal sunshades was made by using 3D printing technology and dozens of pressure taps were arranged at both sides of overhanging horizontal sunshades to measure wind pressures on the sunshades directly. The distribution of wind pressure of overhanging horizontal sunshades and the effect of the sunshades on the wind pressure of the building facade were studied. The estimation errors of wind pressures of the sunshades based on wind pressures on building facade were evaluated. The test results show that the maximum value of the most unfavorable wind pressure on overhanging horizontal sunshades appears on the highest sunshade near the building top. The overhanging horizontal sunshades can greatly reduce the most unfavorable negative wind pressure on the building facade. The most unfavorable wind pressures on overhanging horizontal sunshades can be approximately estimated by using the wind pressure differences on building facades between upside and downside of the sunshade. However the errors are larger at the end of sunshades near the edges of building facade and on the lowest sunshades near the bottom of building.