以力平衡儀氣動力實驗探討方柱與圓柱之干擾效應

現今高樓林立，且越高之建築物受風力影響越大，而高樓與高樓之間存在相互影響關係，因此本研究選用兩種幾何斷面(方柱及圓柱)、不同干擾位置及不同風場的模擬，進行高層建築物的風力和結構干擾效應探討。　　本研究試驗，採用氣動力之方式，將高剛性縮尺模型置於一具高自然振動頻率之六力力平衡儀上，同步量測六力瞬時資料。其中瞬時資料包含基底剪力(Base shear)、基底彎矩(Base moment)和扭矩(Torque)。模型選用方形與圓形斷面之三維模型，固定模型高0.6 m，且保持兩模型的斷面積0.01 m^2。風場模擬選用我國《建築物耐風設計規範及解說》中三種標準地況，參考風速為固定模型高9.2 m/sec。數據電壓值經電腦計算轉換為各風力統計值，並利用頻譜分析理論計算結構物的擾動位移和擾動加速度反應。　　本研究數據分析，分為等高線分布圖分析與特定位置干擾分析兩種。等高線分布圖以兩相同斷面組合研究，探討三種不同模擬風場與不同間距之干擾效應；特定位置干擾以四種斷面組合研究，探討C地況下，五個系列不同間距之干擾效應。最後研究結果發現，風力反應與結構反應干擾效應是存在兩高層建築之間，且風力反應與結構反應之干擾效應發現結果不盡相同，甚至同樣位置之干擾效應風力反應減小、結構反應放大。兩高層間之干擾效應，與流場紊流強度、流場α指數、主要建物斷面幾何與干擾建物斷面幾何息息相關。

關鍵字

大氣邊界層風洞；高層建築；力平衡儀；干擾效應；干擾因子

並列摘要

Nowadays, since the urban population density is high, skyscrapers have become more and more common. There is an interference effect between the neighboring buildings. The wind force response and structural response may either decrease or increase on principal building. The high rise building interference effect depends mainly on the geometry, terrain, and distance between two buildings. This research investigates the interference effect between two neighboring buildings by comparing its interfered wind force and structure response. First of all, the wind tunnel experiment used models with identical volumes and height but different cross sectional geometries. The models are 60 centimeters high and made in square and circular section of 100 square centimeters for the principal and interfering building. Secondly, the flow velocity remains at 9.2 m/s at the height of the model. In addition, there are three standard terrains of A, B, and C terrain in the experiment. Finally, the sampling data is used to calculate wind force coefficients, structure responses, wind force interference factors, and structure response interference factors. This research investigates interference effect between two buildings of same geometries by using contour, and investigates interference effect between buildings of four different geometries with terrain C. As mentioned above, this research has shown that wind forces and structure responses are disturbed by different geometries, terrains, and distances between two buildings.