干擾效應對高層建築設計風力的影響

The Interference Effects on the design wind loads of high-rise buildings

林倚仲(Yi-Jong Lin)

指導教授 ： 鄭啟明

淡江大學/工學院/土木工程學系碩士班/碩士(2005年)

https://doi.org/10.6846/TKU.2005.00749

摘要

現今社會隨著有限的土地與空間不斷減少下，建築物往上發展成為主要的趨勢，高層建築除了受地震力之外，風力作用也是重要的受力載重。由於高層建築不斷的增加，所以在高樓林立之現今大都市中，相鄰建築物間之交互作用便成為一重要的問題。
本文主要是探討干擾效應對高層建築設計風載重之影響和修正模式建立，風洞試驗時將干擾模型置於主要量測建築物前，改變干擾模型之位置，然後比較不同干擾模型位於不同位置時風力之差異，並以實驗數據做為修正依據，建立一修正式。干擾實驗類型分別為:1. 改變干擾建物高寬比系列 2. 改變主要量測建物斷面形狀系列。風洞實驗使用力平衡儀量測單一建築模型以及在各種干擾效應下的風力。本文根據實驗數據，計算建築物在順風向與橫風向的平均風力與擾動風力干擾係數。並配合原型高層建築結構特性，計算出結構物之設計風載重。
由本文實驗結果得知，在干擾效應下之設計風載重方面，在距離量測建物橫向約3到4倍的迎風面寬度，放置干擾建物會使得量測建物設計風力有放大的現象。渦散頻率方面，則是干擾建物改變寬度系列，對於渦散頻率會有明顯的影響。本文就靜態干擾係數與動態干擾係數建立的修正模式，應用於干擾建物高寬比或主要量測建物改變斷面的條件下。若兩種條件同時發生，則本修正模式並不試用。

關鍵字

高層建築 ； 風洞實驗 ； 干擾效應 ； 設計風載重

並列摘要

High-rise building plays an important role in the city development due to the limited land. In addition to the earthquake force, wind force becomes an important lateral design load for high-rise buildings. The increasing number of high-rise buildings in a large city makes the interference effects between the adjacent buildings becomes an important wind engineering problem. This paper investigates the interference effect on the design wind load of high-rise buildings. The wind tunnel experiments were conducted for different model geometry shapes and various model spacing in a grid system. The wind tunnel experiments can be categorized into two groups: (1) interference effects of inferring buildings with identical volumes but different cross-sectional shapes, (2) interference effects of inferring buildings have the same height but different building width. Design wind load were calculated for comparison. High frequency force balance was used to measure both the mean and dynamic wind loads. The interference factors for mean and dynamic wind loads on both along-wind and across-wind directions were evaluated.
The experimental results indicate that the adjacent building casts significant interference effect on the design wind load in general. When the target building was located 3~4 width from the influence of building has the biggest design wind load. The presence of the adjacent building could have noticeable effect on the vortex shedding characteristics and consequently the vortex related wind loads. A design wind load modification procedure in consideration of the interference effects is derived based on the present study. The predicted wind load agrees well with the direct measurement when the geometry of the interfering building has only minor deviation from the model used in the current wind tunnel study.

並列關鍵字

high-rise building ； wind tunnel ； interference effect ； design wind load

參考文獻

11. Armitt, J. & Counihan, J., 1968, " The Simulation of the Atmospheric Environment ", Vol.2.﹐pp.49-71.

12. Counihan﹐J.﹐1970﹐" An Improved Method of Simulation Atmospheric Boundary Layer "﹐Atmospheric Environment﹐Vol.4﹐pp.159-275.

13. Counihan﹐J.﹐1970﹐" Further Measurements in a Simulated Atmospheric Bounday Layer "﹐Atmospheric Environment﹐Vol.4﹐pp.159-275.

14. Counihan﹐J.﹐1973﹐" Simulation of an Adiabatic Urban Boundary Layer in a Wind Tunnel "﹐Atmospheric Environment﹐Vol.7﹐pp.673-689.

16. Barret, R. V., 1972, " A Versatile Compact Wind Tunnel for Industrial Aerodynamics"﹐ Technical note﹐Atmospheric Environment﹐Vol.6﹐ pp.491-495.