對於不同幾何建築物在干擾效應下之設計風載重的影響

The Interference Effects on the design wind loadsof Different buildings

杜富元(Fu-Yuan Du)

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(2012年)

https://doi.org/10.6846/TKU.2012.01021

摘要

在高樓林立的現代都市裡，大樓的密度升高不少，以往將低矮房屋改建成大樓時並不需要考慮其他建築物對於自身的影響，但隨著高樓密度提高，很多大樓已經是並排在一起，甚至更有不少棟連在一起或是相鄰附近。故遮蔽效應之影響不能小覷。
目前國內的風力規範是以經驗公式來做設計風載重，但無法有系統地呈現完成風的變化，尤其是對於風的來向、周遭地形的變化…等等，這些必須透過風洞試驗方能夠對於這些變化有效的模擬，以彌補單就風力規範對於計算設計風載重的不足。
本研究主要是以風洞試驗探討干擾效應對高層建築設計風載重之影響，最後再利用所量測出干擾係數來計算出設計風載重，探討方向分為；
第一部份在探討量體對於干擾效應下之影響，透過風洞試驗所量測到之各項固定量體之干擾係數，與前人所量測之未固定量體之干擾係數做比較，討論其影響。
第二部份主要是以風洞試驗來探討改變干擾建物高寬比系列，可分為主要建物寬深比2/1、3/1。風洞試驗時將干擾模型至於主要量測建築物之風力變化，並以實驗數據為準，透過程式計算出各項干擾係數來做比較，最後在經由第二部分所得之各項干擾係數，經由Matlab程式計算出設計風載重，透過設計風載重。
由本文實驗結果得知，干擾建物高度與寬度不同時，對於下游主要建物的風力會產生不同的影響。在 X/B=3，Y/B=0的位置時，可觀察到，改變高度對於平均風力的影響較改變寬度影響來的小。
在干擾效應下，在順風向(X/B=3~13,Y/B=0)上均有變小的效果，大部份之擾動風力係數均會大於單一建築，尤其是橫風向(X/B=3~13,Y/B=0~2)，放大最為明顯。在設計風載重下，C地況影響最大，B地況其次，A地況最小。

關鍵字

高層建築 ； 風洞試驗 ； 干擾效應 ； 設計風載重

並列摘要

In the modern city, tall buildings are usually built in cluster. The interference effect caused by the adjacent tall buildings that may significantly increase the wind loads becomes an important factor to be taken into consideration during building design. This research conducted systematic wind tunnel tests to investigate the interference effect of two adjacent tall buildings with various separations and geometric shapes.
The initial part of this thesis investigates the effect of building volume on the interference coefficient. The results indicate that the variation of building volume caused by change of cross-sectional depth has little effect on the interference phenomenon. Based on this finding, only the height ratio and breadth ratio were used as the geometric parameters in the subsequent wind tunnel studies.
Then this thesis study the interference effect on principal buildings with aspect ratio H/√A=6 and side ratio D/B=1/3, 1/2, 2/1, 3/1, in turbulent boundary layers developed over urban, suburban and open country terrain categories. Whereas the interfering building has the various height ratios and breadth ratios with respect to the principal building. Wind loads acting on the principal building under the influence of the adjacent inferring building were measured and converted to interference coefficients by normalization with respect to the corresponding wind loads of an isolated building.
The results indicate that change of building height and width of the interfering building will cast different level of effect on the principal building. Generally speaking, breadth of the interfering building causes more interference effects than the building height. Under interference, the mean alongwind load tends to decrease due to the shielding of the upstream interfering building. However, the fluctuating wind loads, especially the acrosswind load, tend to increase due to the presence of the adjacent interfering building for the most cases. As for the building design wind loads, building in open country is subjected to the strongest inference effect, and building in urban terrain the least.

並列關鍵字

High-rise building ； Wind tunnel ； interference effect ； Design wind load

參考文獻

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